U.S. patent application number 16/196965 was filed with the patent office on 2019-05-23 for firearm projectiles with turbulence-inducing surfaces, firearm cartridges including the same, and associated methods.
The applicant listed for this patent is Amick Family Revocable Living Trust. Invention is credited to Darryl D. Amick.
Application Number | 20190154421 16/196965 |
Document ID | / |
Family ID | 66532257 |
Filed Date | 2019-05-23 |
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United States Patent
Application |
20190154421 |
Kind Code |
A1 |
Amick; Darryl D. |
May 23, 2019 |
FIREARM PROJECTILES WITH TURBULENCE-INDUCING SURFACES, FIREARM
CARTRIDGES INCLUDING THE SAME, AND ASSOCIATED METHODS
Abstract
Firearm projectiles with turbulence-inducing surfaces, firearm
cartridges including the same, and associated methods. A firearm
projectile comprises a projectile body and a turbulence-inducing
surface at least substantially enclosing the projectile body. The
firearm projectile is at least substantially spherical. The
turbulence-inducing surface is configured to induce a drag crisis
in a drag coefficient of the firearm projectile when the firearm
projectile travels through air with a Reynolds number that is less
than 300,000.
Inventors: |
Amick; Darryl D.; (Albany,
OR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Amick Family Revocable Living Trust |
Albany |
OR |
US |
|
|
Family ID: |
66532257 |
Appl. No.: |
16/196965 |
Filed: |
November 20, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62707888 |
Nov 21, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F42B 7/046 20130101;
F42B 10/38 20130101 |
International
Class: |
F42B 10/38 20060101
F42B010/38; F42B 7/04 20060101 F42B007/04 |
Claims
1. (canceled)
2. The shot shell of claim 12, wherein when a shot pellet of the
plurality of shot pellets traveling through air has a Reynolds
number that is less than 300,000, the shot pellet has a drag
coefficient that is less than 0.35.
3. The shot shell of claim 12, wherein each shot pellet of the
plurality of shot pellets has a drag coefficient when traveling
through air at a given velocity that is at most 0.7 times a drag
coefficient of a smooth spherical projectile of the same mass and
material composition as the shot pellet and that lacks the
turbulence-inducing surface when the smooth spherical projectile
travels through air with the given velocity.
4. The shot shell of claim 12, wherein the turbulence-inducing
surface of each of the plurality of shot pellets is integral with
the respective projectile body of each of the plurality of shot
pellets.
5. The shot shell of claim 12, wherein the turbulence-inducing
surface of each of the plurality of shot pellets consists of a
plurality of non-overlapping surface loci; wherein each surface
locus of the plurality of surface loci has a corresponding locus
radius, as measured between the surface locus and a center point of
the projectile body; wherein each shot pellet of the plurality of
shot pellets has a reference radius that is equal to the arithmetic
mean of the corresponding locus radii of the plurality of surface
loci; wherein each surface locus of the plurality of surface loci
further has a corresponding radial deviation that is equal to the
corresponding locus radius minus the reference radius; wherein each
shot pellet of the plurality of shot pellets is characterized by a
roughness metric that is based, at least in part, on the set of
corresponding radial deviations of the plurality of surface loci;
wherein the roughness metric includes a relative roughness ratio,
defined as the ratio of a characteristic roughness depth of the
turbulence-inducing surface to a diameter of the shot pellet;
wherein the characteristic roughness depth is equal to an
arithmetical mean deviation, defined as the arithmetic mean of the
absolute values of the set of corresponding radial deviations of
the plurality of surface loci; and wherein the absolute value of
the relative roughness ratio is at least 0.0001 and at most
0.035.
6. The shot shell of claim 5, wherein the plurality of surface loci
includes at least 10,000 surface loci.
7. The shot shell of claim 12, wherein the turbulence-inducing
surface of each shot pellet of the plurality of shot pellets
includes a plurality of localized surface features, wherein each
localized surface feature includes at least one of a depression, an
indentation, and a crater.
8. The shot shell of claim 7, wherein at least one localized
surface feature includes a depression that is at least
substantially surrounded by a raised rim.
9. The shot shell of claim 12, wherein the turbulence-inducing
surface of each shot pellet of the plurality of shot pellets
includes a plurality of elongate surface features, wherein each
elongate surface feature includes at least one of a ridge, an edge,
a channel, a groove, and a scratch.
10. The shot shell of claim 9, wherein the plurality of elongate
surface features includes a plurality of scratches that are
randomly oriented with respect to one another.
11. The shot shell of claim 9, wherein the plurality of elongate
surface features include at least one of intersecting and partially
overlapping surface features.
12. A shot shell, comprising: a casing that defines an internal
volume; a propellant disposed in the internal volume; a primer
disposed in the internal volume and configured to ignite the
propellant; a wad disposed in the internal volume and separating
the propellant and the primer from a payload region of the shot
shell; and a plurality of shot pellets received within the payload
region of the shot shell, each of the plurality of shot pellets is
at least substantially spherical and comprises: a projectile body;
and a turbulence-inducing surface at least substantially enclosing
the projectile body; wherein the turbulence-inducing surface of
each shot pellet of the plurality of shot pellets is configured to
induce a drag crisis in a drag coefficient of the shot pellet when
the shot pellet traveling through air has a Reynolds number that is
less than 300,000.
13. (canceled)
14. The shot shell of claim 12, wherein the shot shell is
configured to propel the plurality of shot pellets with a muzzle
velocity that is at least 350 meters per second (1,148 feet per
second).
15. A method of manufacturing each shot pellet of the plurality of
shot pellets of claim 12, the method comprising: providing a base
projectile that is at least substantially spherical, wherein the
base projectile includes a smooth exterior surface; and forming the
turbulence-inducing surface on the exterior surface of the base
projectile.
16. The method of claim 15, wherein the providing the base
projectile includes providing a projectile precursor that is not
substantially spherical and shaping the projectile precursor into
the base projectile that is at least substantially spherical.
17. The method of claim 15, wherein the forming the
turbulence-inducing surface includes chemically etching the
exterior surface of the base projectile with an acid.
18. The method of claim 15, wherein the forming the
turbulence-inducing surface includes mechanically deforming the
exterior surface of the base projectile.
19. The method of claim 18, wherein the mechanically deforming the
exterior surface of the base projectile includes mechanically
abrading the exterior surface of the base projectile via a shear
process by rolling the base projectile relative to an abrasive
belt.
20. The method of claim 18, wherein the mechanically deforming the
exterior surface of the base projectile includes abrasively
blasting the exterior surface of the base projectile with an
abrasive medium that includes one or more of air, water, sand,
grit, and pellets.
21. The shot shell of claim 12, wherein each shot pellet of the
plurality of shot pellets has a diameter that is at least 2
millimeters (mm) and that is at most 10 mm.
22. The shot shell of claim 12, wherein each shot pellet of the
plurality of shot pellets has a density that is at least 6.5 grams
per cubic centimeter (g/cc).
23. The shot shell of claim 1, wherein the turbulence-inducing
surface of each shot pellet of the plurality of shot pellets
includes a plurality of at least partially overlapping depressions,
indentations, and/or craters.
24. The shot shell of claim 12, wherein at least 95 wt % of each
shot pellet of the plurality of shot pellets is metal.
Description
RELATED APPLICATION
[0001] The present application claims priority under 35 U.S.C.
.sctn. 119(e) to U.S. Provisional Patent Application No.
62/707,888, which was filed on Nov. 21, 2017, the disclosure of
which is hereby incorporated by reference.
FIELD
[0002] The present disclosure relates generally to the field of
firearm ammunition.
BACKGROUND
[0003] Firearm projectiles generally are configured to travel
through air at high velocities, such as velocities exceeding 400
meters per second (m/s). As a firearm projectile travels through
air, drag forces act to reduce the velocity of the projectile such
that the velocity of the projectile upon reaching a target is
diminished significantly relative to the initial (muzzle) velocity
of the projectile. Accordingly, firearm cartridges must include
sufficient propellant to ensure that the firearm projectile retains
sufficient velocity upon reaching its target. However, increasing
the charge of propellant within a firearm cartridge also may serve
to increase a material cost of the cartridge, and the
correspondingly increased setback forces upon firing the cartridge
may introduce excessive recoil felt by the shooter and/or unwanted
wear to the firearm and/or projectile.
[0004] To optimize velocity retention during the flight of a
firearm projectile, it generally is desirable to minimize the drag
forces exerted upon the projectile during flight, such as by
minimizing a drag coefficient of the projectile. While the drag
coefficient of a given object generally depends on a variety of
factors, it generally is believed that a perfectly smooth sphere
may optimize drag coefficient for a given projectile mass while
retaining ballistic properties, such as grouping of shot pellets.
However, in some circumstances, introducing roughness onto the
surface of a spherical projectile can lead to a reduction in the
drag coefficient of the projectile, such as by disrupting an
airflow immediately adjacent to the projectile. Thus, there exists
a need for firearm projectiles with turbulence-inducing surfaces
that are configured to reduce the draft coefficient of the
projectile.
SUMMARY
[0005] Firearm projectiles with turbulence-inducing surfaces,
firearm cartridges including the same, and associated methods are
disclosed herein. A firearm projectile comprises a projectile body
and a turbulence-inducing surface at least substantially enclosing
the projectile body. The firearm projectile is at least
substantially spherical. The turbulence-inducing surface is
configured to induce a drag crisis in a drag coefficient of the
firearm projectile when the firearm projectile has a Reynolds
number that is less than 300,000 while traveling through air after
a firearm cartridge containing the projectile is fired from a
firearm. The methods may include providing a base projectile that
has a smooth exterior surface and which may be at least
substantially spherical, and then forming a turbulence-inducing
surface on the exterior surface of the base projectile. The forming
may include one or more of removing material from the exterior
surface, adding material to the exterior surface, and deforming the
exterior surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic representation of an example of a
firearm projectile according to the present disclosure.
[0007] FIG. 2 is a graph illustrating plots of drag coefficient as
a function of Reynolds number for spheres of varying degrees of
surface roughness.
[0008] FIG. 3 is a schematic representation of examples of firearm
projectiles with various types of turbulence-inducing surfaces
according to the present disclosure.
[0009] FIG. 4 is an illustration of an example of a firearm
projectile with a turbulence-inducing surface in the form of a
chemically etched surface according to the present disclosure.
[0010] FIG. 5 is an illustration of an example of a firearm
projectile with a turbulence-inducing surface in the form of a
mechanically abraded surface according to the present
disclosure.
[0011] FIG. 6 is an illustration of an example of a firearm
projectile with a turbulence-inducing surface in the form of an
abrasively blasted surface according to the present disclosure.
[0012] FIG. 7 is a schematic fragmentary cross-sectional
representation of an example of a firearm projectile with a
turbulence-inducing surface according to the present
disclosure.
[0013] FIG. 8 is a schematic representation of an example of a
firearm cartridge in the form of a shot shell that contains a
plurality of firearm projectiles in the form of shot pellets
according to the present disclosure.
[0014] FIG. 9 is a flow chart illustrating examples of methods for
forming firearm projectiles and firearm cartridges according to the
present disclosure.
DETAILED DESCRIPTION
[0015] FIGS. 1-9 provide examples of firearm projectiles 100 with
turbulence-inducing surfaces 120 according to the present
disclosure, of firearm cartridges 10 that include projectiles 100,
of turbulence-inducing surfaces 120, and/or of methods 200 for
forming firearm projectiles 100 and/or firearm cartridges 10.
Elements that serve a similar, or at least substantially similar,
purpose are labeled with like numbers in each of FIGS. 1-9, and
these elements may not be discussed in detail herein with reference
to each of FIGS. 1-9. Similarly, all elements may not be labeled in
each of FIGS. 1-9, but reference numbers associated therewith may
be utilized herein for consistency. Elements, components, and/or
features that are discussed herein with reference to one or more of
FIGS. 1-9 may be included in and/or utilized with the subject
matter of any of FIGS. 1-9 without departing from the scope of the
present disclosure.
[0016] In general, elements that are likely to be included in a
given (i.e., a particular) embodiment are illustrated in solid
lines, while elements that are optional to a given embodiment are
illustrated in dashed lines. However, elements that are shown in
solid lines are not essential to all embodiments, and an element
shown in solid lines may be omitted from a given embodiment without
departing from the scope of the present disclosure.
[0017] FIG. 1 schematically illustrates an example of a firearm
projectile 100 according to the present disclosure. As
schematically illustrated in FIG. 1, firearm projectile 100
includes a projectile body 110 and a turbulence-inducing surface
120 that at least substantially encloses, or covers, projectile
body 110. Turbulence-inducing surface 120 additionally or
alternatively may be described as forming at least a portion of,
and optionally at least a substantial portion or all of, the
exterior surface of firearm projectile 100. Turbulence-inducing
surface 120 generally is configured to optimize drag properties of
firearm projectile 100 during ballistic flight thereof, as
described herein. While projectile body 110 and turbulence-inducing
surface 120 generally are described herein as being distinct
components of firearm projectile 100, it is within the scope of the
present disclosure that projectile body 110 and turbulence-inducing
surface 120 refer to respective regions, portions, and/or features
of firearm projectile 100. For example, projectile body 110 and
turbulence-inducing surface 120 may be formed of the same material.
As a more specific example, turbulence-inducing surface 120 may be
formed of the same material as the projectile body and may be
integral with projectile body 110. In such examples,
turbulence-inducing surface 120 may refer and/or correspond to a
surface region of firearm projectile 100 such that projectile body
110 is continuous with turbulence-inducing surface 120.
[0018] As described in more detail herein, turbulence-inducing
surface 120 generally is configured to reduce a drag coefficient of
firearm projectile 100, such as relative to an otherwise identical
firearm projectile that lacks the turbulence-inducing surface.
Accordingly, firearm projectiles 100 with turbulence-inducing
surfaces 120 fired from a firearm with a given initial (muzzle)
velocity may travel farther, may retain a greater proportion of
their initial velocity upon impacting a target, may deliver a
greater kinetic energy to a target, and/or may deliver a greater
lethality per firearm projectile, when compared to conventional
firearm projectiles that lack turbulence-inducing surfaces 120 as
described herein. Additionally or alternatively, firearm cartridges
that include firearm projectiles 100 as described herein may
include less propellant and/or fewer firearm projectiles relative
to conventional firearm cartridges that include firearm projectiles
without turbulence-inducing surfaces while retaining performance
metrics (such as lethality per cartridge and/or lethality per
firearm projectile) similar to those of conventional firearm
cartridges with firearm projectiles that do not include
turbulence-inducing surfaces 120.
[0019] As schematically illustrated in FIG. 1, firearm projectile
100 may be a shot pellet 150 that is at least substantially
spherical with a diameter 102. However, this is not required to all
examples of firearm projectile 100, and it is additionally within
the scope of the present disclosure that firearm projectile 100 may
be any appropriate firearm projectile that includes
turbulence-inducing surface 120. Additionally or alternatively,
firearm projectile 100 may be at least substantially spherical
without also being a shot pellet. Moreover, while the present
disclosure generally relates to examples in which a firearm
projectile is at least substantially spherical, this is not
required to all examples of firearm projectile 100, and it is
additionally within the scope of the present disclosure that
firearm projectile 100 may have any appropriate non-spherical shape
suitable for a firearm projectile. Additionally or alternatively,
it is within the scope of the present disclosure that firearm
projectile 100 may include and/or be a projectile for use in a
military context, such as an artillery shell.
[0020] Firearm projectile 100 may have any appropriate dimensions
and/or material construction. As examples, diameter 102 may have
any appropriate value, examples of which include at least 1
millimeter (mm), at least 1.5 mm, at least 2 mm, at least 2.5 mm,
at least 3 mm, at least 3.5 mm, at least 4 mm, at least 4.5 mm, at
least 5 mm, at least 6 mm, at least 7 mm, at least 8 mm, at least 9
mm, at least 10 mm, at least 15 mm, at least 20 mm, at most 25 mm,
at most 17 mm, at most 12 mm, at most 9.5 mm, at most 8.5 mm, at
most 7.5 mm, at most 6.5 mm, at most 5.5 mm, at most 4.7 mm, at
most 4.2 mm, at most 3.7 mm, at most 3.2 mm, at most 2.7 mm, at
most 2.2 mm, at most 1.7 mm, and/or at most 1.2 mm.
[0021] Firearm projectile 100, projectile body 110, and/or
turbulence-inducing surface 120 may be formed of any appropriate
material(s). For example, firearm projectile 100, projectile body
110, and/or turbulence-enhancing surface 120 may be at least
substantially formed from metal, with more specific examples
including at least 90%, at least 93%, at least 95%, at least 97%,
at least 98%, at least 99%, 90-96%, 93-97%, 95-98%, 96-99.5%, or
100% of firearm projectile 100, projectile body 110, and/or
turbulence-enhancing surface 120 being formed from metal. Examples
of suitable metals include one or more of lead, steel, iron,
copper, zinc, nickel, tungsten, bismuth, tin, cobalt, aluminum,
steel, bronze, manganese, and/or alloys and/or mixtures thereof. In
examples in which firearm projectile 100, projectile body 110,
and/or turbulence-inducing surface 120 is not entirely formed from
metal, the remaining portion of firearm projectile 100, projectile
body 110, and/or turbulence-inducing surface 120 may be formed from
other suitable non-metallic components, such as a wax, binder,
corrosion inhibitor, anti-sparking agent, sealant, and/or oxidation
inhibitor. Examples of compositions for firearm projectiles 100,
projectile bodies 110, and/or turbulence-inducing surfaces 120 are
disclosed in U.S. Pat. Nos. 9,528,804, 8,171,849, 7,267,794,
7,059,233, 6,527,880, and 6,447,715, the disclosures of which are
hereby incorporated by reference for all purposes.
[0022] Firearm projectile 100 may have any appropriate mass
density, examples of which include at least 6 grams per cubic
centimeter (g/cc), at least 6.5 g/cc, at least 7 g/cc, at least 7.5
g/cc, at least 8 g/cc, at least 8.5 g/cc, at least 9.0 g/cc, at
least 9.5 g/cc, at most 10 g/cc, at least 10.5 g/cc, at least 11
g/cc, at least 11.5 g/cc, at least 12 g/cc, at least 13 g/cc, at
least 13.5 g/cc, at least 14 g/cc, at least 14.5 g/cc, at least 15
g/cc, at most 16 g/cc, at most 15 g/cc, at most 14 g/cc, at most 13
g/cc, at most 12 g/cc, at most 11.5 g/cc, at most 11 g/cc, at most
10 g/cc, at most 9.5 g/cc, at most 9 g/cc, at most 8.5 g/cc, at
most 8.0 g/cc, at most 7.5 g/cc, and/or at most 7.0 g/cc. As
discussed herein, firearm projectile 100 may have a mass density
that is less than that of conventional firearm projectiles, such as
lead-based firearm projectiles, but which may deliver similar
and/or augmented kinetic energy and/or lethality to a target by
virtue of improved velocity retention during flight thereof.
[0023] Turbulence-inducing surface 120 may be configured to
optimize the ballistic and/or aerodynamic properties of firearm
projectile 100 in any appropriate manner, such as by reducing a
drag force exerted upon the firearm projectile as the projectile
travels through air. As will be appreciated by one skilled in the
art of fluid dynamics, the magnitude of the drag force F.sub.D
exerted upon an object traveling through a fluid may be expressed
as F.sub.D=.rho.u.sup.2C.sub.DA, where .rho. is the mass density of
the fluid, u is the velocity of the object relative the fluid,
C.sub.D is a drag coefficient, and A is the cross-sectional area of
the object. Thus, for a projectile of a given diameter traveling
through air with a given velocity, the drag force generally is
directly proportional to the drag coefficient.
[0024] Turbulence-inducing surface 120 generally is configured to
reduce a drag coefficient of firearm projectile 100 relative to
that of a smooth spherical projectile of the same material
composition and mass as firearm projectile 100, thereby reducing
the drag force exerted upon firearm projectile 100 when traveling
through a given fluid with a given velocity. For example, and as
schematically illustrated in FIG. 1 and as discussed in more detail
herein, turbulence-inducing surface 120 may include a plurality of
surface features 160, such as may be collectively configured to
reduce a drag coefficient of firearm projectile 100. As discussed
herein, the drag coefficient of a given object generally depends
upon a velocity of the object with respect to a fluid medium
through which the object travels. Accordingly, firearm projectile
100 may be described more specifically as having a drag coefficient
when traveling through air at a given velocity that is less than a
drag coefficient of a smooth spherical projectile of the same mass
and material composition as firearm projectile 100 and that lacks
turbulence-inducing surface 120 when the smooth spherical
projectile travels through air with the given velocity. As yet more
specific examples, firearm projectile 100 may have a drag
coefficient, when traveling through air at a given velocity, that
is at least 0.1 times, at least 0.25 times, at least 0.35 times, at
least 0.45 times, at least 0.55 times, at least 0.65 times, at
least 0.75 times, at least 0.85 times, at most 0.9 times, at most
0.8 times, at most 0.7 times, at most 0.6 times, at most 0.5 times,
at most 0.4 times, at most 0.3 times, and/or at most 0.2 times a
drag coefficient of the smooth spherical projectile of the same
mass and material composition as firearm projectile 100.
[0025] As used herein, references to firearm projectile 100
traveling through air, and numerical quantities associated
therewith, generally may refer to examples in which the firearm
projectile travels through air at sea level pressure (e.g., at a
pressure of 101,325 Pascals) and at 0.degree. Celsius. However,
this is not required to all examples of firearm projectile 100, and
it is additionally within the scope of the present disclosure that
firearm projectile 100 may exhibit advantageous ballistic
properties as described herein when traveling through air that has
any appropriate temperature and/or pressure.
[0026] As used herein, the term "velocity," as used to characterize
a flow of fluid around an object or a motion of an object through a
fluid, is intended to refer to a magnitude of a relative speed
between the object and the fluid. Examples (such as numerical
examples) of velocities provided herein may refer to and/or be
determined via any appropriate measurement technique, such as may
be applicable and/or known to the field of firearm ballistics. As
examples, a velocity of firearm projectile 100 subsequent to being
fired from a firearm may be determined via any appropriate
mechanism, examples of which include Doppler measurements, laser
measurements, photographic measurements, and/or kinematic
measurements. As more specific examples, a velocity of firearm
projectile 100 may be determined via measurement of a penetration
of the firearm projectile into a ballistic gel of a known density.
Additionally or alternatively, a velocity of firearm projectile 100
may be determined via a ballistic pendulum apparatus. As further
examples, a velocity of firearm projectile 100 through a fluid may
refer to a velocity of a fluid (such as air) that is propelled
relative to a substantially stationary firearm projectile, such as
by mounting the firearm projectile in a wind tunnel apparatus. In
such an example, the wind tunnel apparatus also may be configured
to provide a direct measurement of a drag force exerted upon
firearm projectile 100 by the fluid flow at a given fluid
velocity.
[0027] As used herein, references to turbulence-inducing surface
120 yielding firearm projectile 100 with a reduced, lower,
increased, higher, improved, augmented, etc. aerodynamic property
(such as a lower drag coefficient and/or a greater velocity upon
impact) generally refer to a comparison between firearm projectile
100 and an otherwise identical firearm projectile that lacks
turbulence-inducing surface 120. As examples, the otherwise
identical firearm projectile may have the same mass, density,
diameter, and/or material construction as firearm projectile 100,
and/or may have an exterior surface that is smooth, such as
substantially smooth, perfectly smooth, substantially spherical,
and/or perfectly spherical.
[0028] The drag coefficient of a given object traveling through a
fluid with a given velocity generally is dependent upon the
velocity of the object relative to the fluid. As will be
appreciated by one skilled in the art of fluid dynamics, the
behavior of the flow of a conventional fluid such as air around a
solid body traveling through the fluid may be characterized as
"laminar," which generally is associated with lower velocities, or
"turbulent," which is generally associated with higher velocities.
As discussed in more detail herein, the relationship between drag
coefficient and velocity may vary depending upon whether the fluid
flow is in a laminar regime or a turbulent regime. These distinct
regimes of fluid flow may be characterized via reference to the
dimensionless Reynolds number (Re), defined as Re=uD/v, where u is
the velocity of the object relative to the fluid, D is the diameter
of the object, and v is the kinematic viscosity of the fluid. Thus,
for a given object with a given diameter traveling through a given
fluid, the Reynolds number is directly proportional to the relative
velocity between the object and the fluid.
[0029] As used herein, the terms "turbulence" and "turbulent," as
used to describe a flow characteristic of a fluid, refer generally
to a flow state in which flow characteristics (such as pressure
and/or flow velocity) are chaotic, random, and/or disordered. In
this manner, turbulent flow generally stands in contrast to laminar
flow, which in turn refers generally to a flow state in which fluid
flow exhibits ordered, parallel layers. A transition between
laminar flow and turbulent flow may occur in a spatial sense, for
example, such as in which a fluid flow around an object exhibits
regions of laminar flow and regions of turbulent flow. Additionally
or alternatively, a transition between laminar flow and turbulent
flow may occur in a dynamic sense, for example, such as in which
increasing the velocity of an object through a fluid serves to
introduce turbulence into a region, relative to the object, that
exhibits laminar flow at lower velocities. Accordingly, as used
herein, the phrase "inducing turbulence" (and the like) generally
may refer to an onset in turbulent flow in a region relative to an
object that previously exhibited laminar flow.
[0030] As discussed, the drag coefficient of an object traveling
relative to a fluid with a velocity generally depends on the
velocity, which in turn may be associated with a Reynolds number
describing the flow characteristics. FIG. 2 is a graph illustrating
plots of drag coefficient C.sub.D as a function of the Reynolds
number Re for spheres with varying surface characteristics.
Specifically, curve 1 plots C.sub.D vs. Re for a smooth sphere,
while curves 2-5 plot C.sub.D vs. Re for spheres with increasing
degrees of surface roughness, with curve 5 representing the
greatest degree of surface roughness. As seen in FIG. 2, the drag
coefficient of a smooth sphere falls abruptly from about 0.5 to
about 0.1 at a Reynolds number of about 300,000. This phenomenon,
known in the art of fluid dynamics as the "drag crisis," is
associated with a transition from laminar flow to turbulent flow in
a boundary layer of fluid flow immediately adjacent to the sphere,
thereby narrowing a turbulent wake formed behind the sphere and
reducing a pressure drag exerted on the sphere as a result of the
turbulent wake.
[0031] As used herein, the term "about," as used to characterize a
quantity with respect to a reference number, may indicate that the
quantity is equal to the reference number, is at least
substantially equal to the reference number, falls within an
absolute range relative to the reference number, and/or falls
within a percentage variation relative to the reference number. As
examples, a drag coefficient that is described as being about equal
to a reference drag coefficient may differ from the reference drag
coefficient by a difference of at most 0.1, at most 0.075, at most
0.05, at least 0, and/or 0. As additional examples, a Reynolds
number that is described as being about equal to a reference
Reynolds number may differ from the reference Reynolds number by at
most 40%, at most 30%, at most 20%, at most 10%, at most 5%, at
least 0%, and/or 0%.
[0032] With continued reference to FIG. 2, the velocity-dependent
drag coefficient of a nominally spherical projectile may be altered
via the introduction of surface roughness onto the projectile. As
discussed, introducing roughness onto an exterior surface of a
projectile, such as via turbulence-inducing surface 102, may serve
to introduce turbulence into the boundary flow layer adjacent to
the projectile at lower velocities, thereby shifting a critical
Reynolds number at which the drag crisis occurs to lower values.
Specifically, FIG. 2 illustrates plots of drag coefficient as a
function of Reynolds numbers for spheres characterized by relative
roughness values of 0.15% (curve 2), 0.5% (curve 3), and 1.25%
(curve 4). In the context of FIG. 2, relative roughness is defined
as a ratio of a sand roughness of the sphere to a diameter of the
sphere. Curve 5 is a plot of drag coefficient vs. Reynolds number
for a dimpled sphere, such as a golf ball. As seen in FIG. 2,
increasing a degree of surface roughness may lead to a decrease in
the value of the critical Reynolds number--and, hence, a decrease
in the value of a critical velocity--above which the drag
coefficient of the given projectile falls to a reduced value.
Accordingly, turbulence-inducing surface 120 may be roughened
and/or otherwise configured such that firearm projectile 100 is
expected to travel at velocities in excess of this critical
velocity during its flight, thereby enabling firearm projectile 100
to travel with a reduced drag coefficient during the course of its
flight relative to a substantially smooth spherical projectile of
the diameter 102. As examples, turbulence-inducing surface 120 of
firearm projectile 100 may be configured to induce turbulence in a
boundary layer of air adjacent to the firearm projectile when the
firearm projectile traveling through air has a Reynolds number that
is less than 300,000, less than 200,000, less than 100,000, and/or
greater than 10,000. Additionally or alternatively,
turbulence-inducing surface 120 of firearm projectile 100 may be
configured to induce a drag crisis in the drag coefficient of the
firearm projectile when the firearm projectile traveling through
air has a critical Reynolds number that is less than 300,000, less
than 200,000, less than 100,000, and/or greater than 10,000.
[0033] Firearm projectile 100 may have any appropriate drag
coefficient, such as may depend upon a velocity and/or a Reynolds
number thereof. For example, when firearm projectile 100 traveling
through air has a Reynolds number that is less than 300,000, the
firearm projectile may have a drag coefficient that is less than
0.35. Additionally or alternatively, firearm projectile 100 may be
described as having a drag coefficient that is less than about 0.35
when the firearm projectile traveling through air has a Reynolds
number that is less than a maximum ballistic Reynolds number and
greater than a minimum ballistic Reynolds number. As used herein,
the maximum ballistic Reynolds number may correspond to a maximum
Reynolds number experienced during a flight of firearm projectile
100 (such as immediately after being discharged from the barrel of
a firearm), while the minimum ballistic Reynolds number may
correspond to a minimum Reynolds number experienced during the
flight of the firearm projectile (such as immediately before
impacting a target). As examples, the maximum ballistic Reynolds
number may correspond to the muzzle velocity of firearm projectile
100 (such as 457 m/s (1,500 feet/s)), and/or the minimum ballistic
Reynolds number may correspond to the velocity of the firearm
projectile subsequent to traveling a distance of 36.6 m (40 yards).
More specific examples include the following, which may correspond
to firearm projectiles 100 traveling through air with a pressure of
101,325 Pascals and a temperature of 0.degree. Celsius:
[0034] Example 1: Firearm projectile 100 may be a BBB shot pellet
150 with diameter 102 of 4.83 mm (0.19 inches (in.)), the maximum
ballistic Reynolds number may be about 166,000, and the minimum
ballistic Reynolds number may be about 128,000.
[0035] Example 2: Firearm projectile 100 may be a BB shot pellet
150 with diameter 102 of 4.57 mm (0.18 in.), the maximum ballistic
Reynolds number may be about 157,000, and the minimum ballistic
Reynolds number may be about 119,000.
[0036] Example 3: Firearm projectile 100 may be a B shot pellet 150
with diameter 102 of 4.32 mm (0.17 in.), the maximum ballistic
Reynolds number may be about 148,000, and the minimum ballistic
Reynolds number may be about 112,000.
[0037] Example 4: Firearm projectile 100 may be a #1 shot pellet
150 with diameter 102 of 4.06 mm (0.16 in.), the maximum ballistic
Reynolds number may be about 140,000, and the minimum ballistic
Reynolds number may be about 104,000.
[0038] Example 5: Firearm projectile 100 may be a #2 shot pellet
150 with diameter 102 of 3.81 mm (0.15 in.), the maximum ballistic
Reynolds number may be about 131,000, and the minimum ballistic
Reynolds number may be about 96,800.
[0039] Example 6: Firearm projectile 100 may be a #3 shot pellet
150 with diameter 102 of 3.56 mm (0.14 in.), the maximum ballistic
Reynolds number may be about 122,000, and the minimum ballistic
Reynolds number may be about 89,200.
[0040] Example 7: Firearm projectile 100 may be a #4 shot pellet
150 with diameter 102 of 3.30 mm (0.13 in.), the maximum ballistic
Reynolds number may be about 114,000, and the minimum ballistic
Reynolds number may be about 81,700.
[0041] Example 8: Firearm projectile 100 may be a #5 shot pellet
150 with diameter 102 of 3.05 mm (0.12 in.), the maximum ballistic
Reynolds number may be about 105,000, and the minimum ballistic
Reynolds number may be about 74,200.
[0042] Example 9: Firearm projectile 100 may be a #6 shot pellet
150 with diameter 102 of 2.79 mm (0.11 in.), the maximum ballistic
Reynolds number may be about 96,000, and the minimum ballistic
Reynolds number may be about 66,800.
[0043] Example 10: Firearm projectile 100 may be a #7 shot pellet
150 with diameter 102 of 2.54 mm (0.10 in.), the maximum ballistic
Reynolds number may be about 88,000, and the minimum ballistic
Reynolds number may be about 59,500.
[0044] Example 11: Firearm projectile 100 may be a #71/2 shot
pellet 150 with diameter 102 of 2.41 mm (0.095 in.), the maximum
ballistic Reynolds number may be about 83,000, and the minimum
ballistic Reynolds number may be about 55,800.
[0045] Example 12: Firearm projectile 100 may be a #8 shot pellet
150 with diameter 102 of 2.29 mm (0.090 in.), the maximum ballistic
Reynolds number may be about 79,000, and the minimum ballistic
Reynolds number may be about 52,200.
[0046] Firearm projectile 100 additionally or alternatively may be
described as having a drag coefficient that is at least
substantially constant during flight thereof. As examples, firearm
projectile 100 may have a drag coefficient that is at least
substantially constant, constant to within 50%, and/or constant to
within 20% when the firearm projectile traveling through air has a
Reynolds number that is less than the maximum ballistic Reynolds
number and greater than the minimum ballistic Reynolds number of
the firearm projectile.
[0047] Turning now to FIGS. 3-6, turbulence-inducing surface 120
may include and/or be any appropriate form, quality, dimension,
and/or distribution of surface features 160 for reducing a drag
coefficient of firearm projectile 100 as described herein.
Specifically, FIG. 3 schematically illustrates examples of
turbulence-inducing surfaces 120, while FIGS. 4-6 provide less
schematic illustrations of firearm projectiles 100 in the form of
shot pellets 150 including examples of turbulence-inducing surfaces
120.
[0048] The plurality of surface features 160 may include and/or be
any appropriate features. For example, and as schematically
illustrated in FIG. 3, the plurality of surface features 160 may
include one or more depressions 162 and/or one or more protrusions
164. As examples, each depression 162 may include and/or be an
indentation, a crater, a dimple, an etch, a channel, a groove,
and/or a scratch. As additional examples, each protrusion 164 may
include and/or be a bump, a pimple, a ridge, an edge, and/or a
raised rim. As additionally schematically illustrated in FIG. 3,
turbulence-inducing surface 120 and/or the plurality of surface
features 160 may be described as including one or more localized
surface features, such as depressions 162, indentations, craters,
dimples, protrusions 164, bumps, and/or pimples. Additionally or
alternatively, turbulence-inducing surface 120 may include one or
more elongate surface features, such as ridges, edges, channels,
grooves, and/or scratches. In an example in which
turbulence-inducing surface 120 includes a plurality of elongate
surface features, two or more of the elongate surface features may
be randomly oriented with respect to one another and optionally may
intersect and/or partially overlap. Additionally or alternatively,
two or more of the elongate surface features may be at least
substantially parallel to one another.
[0049] As a more specific example, and as schematically illustrated
in FIG. 3, turbulence-inducing surface 120 may include and/or be an
etched surface 132 in which the plurality of surface features 160
includes a plurality of channels and/or grooves. In such an
example, the plurality of channels and/or grooves also may be
referred to as a network and/or a mosaic of channels and/or
grooves. Etched surface 132 may be formed via any appropriate
process, such as via a chemical etching process, examples of which
are described herein. FIG. 4 illustrates an example of firearm
projectile 100 in the form of shot pellet 150 with
turbulence-inducing surface 120 in the form of etched surface
132.
[0050] As another example, and as further schematically illustrated
in FIG. 3, turbulence-inducing surface 120 may include and/or be a
mechanically abraded surface 134, in which the plurality of surface
features 160 includes a plurality of scratches. Mechanically
abraded surface 134 may be formed via any appropriate process, such
as via a mechanical abrading process, examples of which are
described herein. FIG. 5 illustrates an example of firearm
projectile 100 in the form of shot pellet 150 with
turbulence-inducing surface 120 in the form of mechanically abraded
surface 134 with a plurality of randomly oriented scratches.
[0051] As another example, and as further schematically illustrated
in FIG. 3, turbulence-inducing surface 120 may include and/or be an
abrasively blasted surface 136, in which the plurality of surface
features 160 includes a plurality of depressions 162. In such an
example, at least one depression 162 of the plurality of
depressions may be at least substantially surrounded by a raised
ridge and/or rim, and/or may take the appearance of a crater.
Abrasively blasted surface 136 may be formed via any appropriate
process, such as via an abrasive blasting process, examples of
which are described herein. FIG. 6 illustrates an example of
firearm projectile 100 in the form of shot pellet 150 with
turbulence-inducing surface 120 in the form of abrasively blasted
surface 136 with a plurality of depressions substantially
surrounded by raised rims (e.g., that are raised relative to a
portion of the turbulence-inducing surface immediately adjacent
depression 162).
[0052] As additional examples, and as discussed,
turbulence-inducing surface 120 may include a plurality of
protrusions 164, such as bumps and/or ridges. As more specific
examples, and as further schematically illustrated in FIG. 3,
turbulence-inducing surface 120 may include and/or be a sparsely
textured surface 138, in which the plurality of protrusions 164
includes a plurality of spaced-apart protrusions 164, and/or may
include and/or be a densely textured surface 140, in which the
plurality of protrusions 164 includes a plurality of closely
adjacent and/or at least partially overlapping protrusions 164.
Sparsely textured surface 138 and/or densely textured surface 140
each may be formed via any appropriate respective processes, such
as any of the processes discussed herein. As an additional example,
and as further schematically illustrated in FIG. 3,
turbulence-inducing surface 120 may include and/or be a polyhedral
surface 142, in which the plurality of surface features 160
includes one or more substantially flat facets 166.
[0053] It additionally is within the scope of the present
disclosure that turbulence-inducing surface 120 may include any
appropriate combination of surface features as discussed herein.
For example, turbulence-inducing surface 120 may include a first
surface feature 160 at least partially superimposed upon a second
surface feature 160, in which each of the first surface feature and
the second surface feature is a dimple, a depression, a recess, a
channel, a groove, a ridge, a raised rim, a protrusion, a pimple, a
bump, or a facet.
[0054] Turbulence-inducing surface 120 may be characterized and/or
quantified in any appropriate manner, such as in any appropriate
geometrical, mathematical, and/or statistical manner. For example,
and as schematically illustrated in FIG. 1, turbulence-inducing
surface 120 may be described as consisting of a plurality of
non-overlapping surface loci 122 that collectively form the
turbulence-inducing surface. FIG. 7 is a schematic cross-sectional
representation of turbulence-inducing surface 120 of firearm
projectile 100, segmented into a plurality of surface loci 122. As
schematically illustrated in FIG. 7, each surface locus 122 of the
plurality of surface loci may be described as having a
corresponding locus radius 124, as measured between the surface
locus and a center point 101 of firearm projectile 100. Locus
radius 124 may be measured between center point 101 and any
appropriate point on surface locus 122, such as a center point of
the surface locus. As further schematically illustrated in FIG. 7,
firearm projectile 100 may be characterized by a reference radius
104. Reference radius 104 may be any appropriate dimension of
firearm projectile 100, such as a radius of projectile body 110, a
maximum radius of firearm projectile 100, a minimum radius of the
firearm projectile, and/or the arithmetic mean of the corresponding
locus radii 124 of the plurality of surface loci 122. As further
schematically illustrated in FIG. 7, each surface locus 122 further
may be characterized by a corresponding radial deviation 126 that
is equal to the corresponding locus radius 124 minus the reference
radius 104. Thus, radial deviation 126 may be a positive quantity
or a negative quantity. In this manner, firearm projectile 100
and/or turbulence-inducing surface 120 may be characterized by a
roughness metric that is based, at least in part, on the set of
corresponding radial deviations of the plurality of surface loci
122. As discussed herein, the roughness metric may include and/or
be an individual quantity or a set of quantities, such as a set of
metrics that collectively describe firearm projectile 100 and/or
turbulence-inducing surface 120.
[0055] The roughness metric characterizing turbulence-inducing
surface 120 may include and/or be any appropriate metric and/or
measure corresponding to the set of radial deviations 126. For
example, the roughness metric may include and/or be an arithmetical
mean deviation, defined as the arithmetic mean of the absolute
values of the set of corresponding radial deviations 126 of the
plurality of surface loci 122. Additionally or alternatively, the
roughness metric may include and/or be a root mean squared
deviation, defined as the square root of the arithmetic mean of the
squares of the set of corresponding radial deviations 126 of the
plurality of surface loci 122.
[0056] As additional examples, the roughness metric characterizing
turbulence-inducing surface 120 may include and/or be a normalized
central moment of order n (such that n is an integer greater than
2), defined as the arithmetic mean of the nth power of each of the
corresponding radial deviations 126 of the plurality of surface
loci 122 divided by the nth power of the root mean squared
deviation of the corresponding radial deviations 126 of the
plurality of surface loci 122. As a more specific example, n may be
equal to 3, such that the normalized central moment is a measure of
the skewness of the set of radial deviations 126. In such an
example, the normalized central moment may be a positive quantity
or a negative quantity. As another example, n may be equal to 4,
such that the normalized central moment is a measure of the
kurtosis of the set of radial deviations 126. In general, n may
assume any positive integer value, with higher values of n
corresponding to higher-order normalized central moments that
describe the set of radial deviations 126 with varying degrees of
precision and/or detail.
[0057] As further examples, the roughness metric may include and/or
be a maximum positive deviation and/or a maximum negative
deviation, respectively defined as the maximum value and the
minimum value of the set of corresponding radial deviations 126 of
the plurality of surface loci 122. Additionally or alternatively,
the roughness metric may include and/or be a radial range, defined
as the absolute difference between the maximum positive deviation
and the maximum negative deviation.
[0058] The roughness metric may be understood as characterizing
turbulence-inducing surface 120 in any appropriate manner. For
example, the roughness metric may be at least partially based upon,
and/or may be equal to, a characteristic roughness depth of
turbulence-inducing surface 120. As more specific examples, the
characteristic roughness depth may be equal to a sand roughness,
the arithmetical mean deviation, the root means squared deviation,
the normalized central moment of order n, and/or any other
appropriate measure characterizing turbulence-inducing surface 120.
The characteristic roughness depth may have any appropriate value,
such as for reducing the drag coefficient of firearm projectile 100
as described herein. As example, the characteristic roughness depth
may be at least 1 micrometer (.mu.m), at least 3 .mu.m, at least 5
.mu.m, at least 30 .mu.m, at least 50 .mu.m, at least 100 .mu.m, at
least 300 .mu.m, at least 500 .mu.m, at least 1 mm, at most 2 mm,
at most 700 .mu.m, at most 200 .mu.m, at most 70 .mu.m, at most 20
.mu.m, at most 7 .mu.m, and/or at most 2 .mu.m.
[0059] Additionally or alternatively, the roughness metric may
include and/or be a relative roughness ratio, which may be defined
as the ratio of the characteristic roughness depth of
turbulence-inducing surface 120 to diameter 102 of firearm
projectile 100. The relative roughness ratio may have any
appropriate absolute value, examples of which include at least
0.00001, at least 0.00003, at least 0.00005, at least 0.0001, at
least 0.0003, at least 0.0005, at least 0.001, at least 0.003, at
least 0.005, at least 0.01, at least 0.03, at least 0.05, at most
0.1, at most 0.07, at most 0.035, at most 0.02, at most 0.007, at
most 0.002, at most 0.0007, at most 0.0002, at most 0.00007, and/or
at most 0.00002.
[0060] Turbulence-inducing surface 120 may be described as
including any appropriate number and/or configuration of surface
loci 122. As examples, turbulence-inducing surface 120 may include
at least 100 surface loci 122, at least 1,000 surface loci, at
least 10,000 surface loci, at least 100,000 surface loci, and/or at
most 10,000,000 surface loci. For example, each surface locus 122
may occupy substantially the same solid angle and/or surface area,
and/or may be evenly distributed across turbulence-inducing surface
120. As used herein, the term "solid angle" refers to a measure of
a field of view occupied by a given surface locus 122 as viewed
from center point 101 of firearm projectile 100, such that the
entirety of turbulence-inducing surface 120 occupies a solid angle
of 4.pi.steradians. As examples, each surface locus 122 may occupy
a solid angle that is less than 0.1 steradians, less than 0.01
steradians, less than 0.001 steradians, less than 0.0001
steradians, and/or greater than 0 steradians. Additionally or
alternatively, each surface locus 122 may occupy a surface area
that is less than 1% of a total surface area of turbulence-inducing
surface 120, less than 0.1% of the total surface area of the
turbulence-inducing surface, less than 0.01% of the total surface
area of the turbulence-inducing surface, less than 0.001% of the
total surface area of the turbulence-inducing surface, and/or
greater than 0% of the total surface area of the
turbulence-inducing surface.
[0061] FIG. 7 additionally illustrates examples of surface features
160 that may form and/or be defined by turbulence-inducing surface
120. For example, and as schematically illustrated in FIG. 7, one
or more surface loci 122 may include and/or define a depression 162
with a corresponding depression depth 163. Additionally or
alternatively, one or more surface loci 122 may include and/or
define a protrusion 164 with a protrusion height 165. Depression
depth 163 and/or protrusion height 165 may be defined in any
appropriate manner. For example, depression depth 163 may be
defined as an absolute difference between a minimum radius of
firearm projectile 100 within the corresponding depression 162 and
reference radius 104. Similarly, protrusion height 165 may be
defined as an absolute difference between a maximum radius of
firearm projectile 100 within the corresponding protrusion 164 and
reference radius 104. As more specific examples, each depression
depth 163 and/or each protrusion height 165 may be at least 1
.mu.m, at least 3 .mu.m, at least 5 .mu.m, at least 30 .mu.m, at
least 50 .mu.m, at least 100 .mu.m, at least 300 .mu.m, at least
500 .mu.m, at least 1 mm, at most 2 mm, at most 700 .mu.m, at most
200 .mu.m, at most 70 .mu.m, at most 20 .mu.m, at most 7 .mu.m,
and/or at most 2 .mu.m. Additionally or alternatively, each
depression depth 163 and/or each protrusion height 165 may be less
than, greater than, or equal to the characteristic roughness depth
of turbulence-inducing surface 120.
[0062] FIG. 8 is a schematic example of a firearm cartridge 10 that
includes a plurality of firearm projectiles 100 in the form of shot
pellets 150 according to the present disclosure. A firearm
cartridge 10 that includes at least one shot pellet 150 may be
referred to as a shot shell 14. With reference to FIG. 8, shot
shell 14 is shown including a casing, or housing 18 with a head
portion 24, a hull portion 17, and a mouth region 36. Shot shell 14
further includes an ignition device 25, such as primer, or priming
mixture, 32, which may be configured to ignite propellant 22.
Propellant 22 and primer 32 may be located behind a partition 20,
such as a wad 31, which serves to segregate the propellant and the
primer from a payload 38 of the shot shell and which may provide a
gas seal to impede the flow of propellant gases during firing of
the firearm cartridge.
[0063] Wad 31 may define and/or be described as defining a shot cup
26, which refers to a portion of the wad that generally faces
toward mouth region 36 and which may be contacted by at least a
portion of the plurality of shot pellets 150 in the assembled shot
shell 14. While FIG. 8 illustrates wad 31 as including a shot cup
26 that is curved, this is not required to all examples of wad 31,
and it is additionally within the scope of the present disclosure
that wad 31 may be at least substantially flat. For example, wad 31
may take the form of a flat cylindrical disc. Wad 31 additionally
or alternatively may be referred to as a shot wad 31, and it may
take a variety of suitable shapes and/or sizes. Any suitable size,
shape, material, number of components, and/or construction of wad
31 may be used, including but not limited to conventional wads that
have been used with lead shot, steel shot, and/or other forms of
shot, without departing from the scope of the present
disclosure.
[0064] As indicated in FIG. 8, casing 18 may be described as
defining an internal chamber, internal compartment, and/or enclosed
volume of the shot shell. When the shot shell is assembled, at
least propellant 22, wad 31, and payload 38 are inserted into the
internal compartment, such as through mouth region 36. After
insertion of these components into the internal compartment, mouth
region 36 typically is sealed or otherwise closed, such as via any
suitable closure 35. As an example, the region of the casing distal
head portion 24 may be folded, crimped, or otherwise used to close
mouth region 36.
[0065] Payload 38 additionally or alternatively may be referred to
as a shot charge, or shot load, 38. Payload 38 typically will
include a plurality of shot pellets 150. The region of shot shell
14, casing 18, and/or wad 31 that contains payload 38 may be
referred to as a payload region 39 thereof.
[0066] Wad 31 defines a pellet-facing surface 29 that extends
and/or faces generally toward mouth region 36 and away from head
portion 24 (when the wad is positioned properly within an assembled
shot shell). Wad 31 may include at least one gas seal, or gas seal
region, 27, and at least one deformable region 28, between the
payload region 39 and the propellant 22. Gas seal region 27 is
configured to engage the inner surface of the shotgun's chamber and
barrel to restrict the passage of gasses, which are produced when
the shot shell is fired (i.e., when the charge is ignited), along
the shotgun's barrel. By doing so, the gasses propel the wad, and
the payload 38 of shot pellets 150 contained therein, from the
chamber and along and out of the shotgun's barrel. Deformable
region 28 is designed to crumple, collapse, or otherwise
non-elastically deform in response to the setback, or firing,
forces that are generated when the shot shell is fired and the
combustion of the propellant rapidly urges the wad and payload from
being stationary to traveling down the barrel of the shotgun at
high speeds. Wad 31 may be formed as a single structure or may be
formed from two or more connected, adjacent, or spaced-apart
components.
[0067] A shot shell 14 may include as few as a single shot pellet
150, which perhaps more appropriately may be referred to as a shot
slug, and as many as dozens or hundreds of individual shot pellets
150. The number of shot pellets 150 in any particular shot shell 14
will be defined by such factors as the size and geometry of the
shot pellets, the size and shape of the shell's casing and/or wad,
the available volume in the casing to be filled by shot pellets
150, etc. For example, a 12-gauge double ought (00) buckshot shell
typically contains nine shot pellets having diameters of
approximately 0.3 inches (0.762 cm), while shot shells that are
intended for use in hunting birds, and especially smaller birds,
tend to contain many more shot pellets.
[0068] As discussed, shot shell 14 is designed and/or configured to
be placed within a firearm, such as a shotgun, and to fire payload
38 therefrom. As an example, a firing pin of the firearm may strike
primer 32, which may ignite propellant 22. Ignition of propellant
22 may produce gasses that may expand and provide a motive force to
propel the one or more shot pellets 150 forming payload 38 from the
firearm (or a barrel thereof).
[0069] Shot shell 14 and its components have been illustrated
schematically in FIG. 8 and are not intended to require a specific
shape, size, or quantity of the components thereof. The length and
diameter of the overall shot shell 14 and its casing 18, the amount
of primer 32 and propellant 22, the shape, size, and configuration
of wad 31, the type, shape, size, and/or number of shot pellets
150, etc. all may vary within the scope of the present
disclosure.
[0070] Firearm cartridge 10, such as shot shell 14, may be
configured to propel firearm projectile 100 with any appropriate
initial (muzzle) velocity. As examples, firearm cartridge 10 may be
configured to propel firearm projectile 100 (and/or each of a
plurality of such firearm projectiles) with a muzzle velocity that
is at least 300 meters per second (m/s) (984 feet per second
(ft/s)), at least 350 m/s (1,148 ft/s), at least 400 m/s (1,312
ft/s), at least 450 m/s (1,476 ft/s), at least 500 m/s (1,640
ft/s), at least 550 m/s (1,804 ft/s), at most 600 m/s (1,969 ft/s),
at most 575 m/s (1,886 ft/s), at most 525 m/s (1,722 ft/s), at most
475 m/s (1,558 ft/s), at most 425 m/s (1,394 ft/s), at most 375 m/s
(1,230 ft/s), and at most 325 m/s (1,066 ft/s). Additionally or
alternatively, firearm cartridge 10 may be configured to propel
firearm projectile 100 (and/or each of a plurality of such firearm
projectiles) through air such that the firearm projectile(s)
traveling through air has an initial Reynolds number that is at
least 70,000, at least 80,000, at least 90,000, at least 100,000,
at least 110,000, at least 120,000, at least 130,000, at least
140,000, at least 150,000, at least 160,000, at least 170,000, at
least 180,000, at least 190,000, at most 200,000, at most 195,000,
at most 185,000, at most 175,000, at most 165,000, at most 155,000,
at most 145,000, at most 135,000, at most 125,000, at most 115,000,
at most 95,000, at most 85,000, and/or at most 75,000.
[0071] As discussed, firearm projectile 100 generally may be
configured to exhibit improved velocity retention upon reaching a
target relative to conventional firearm projectiles. Accordingly,
firearm cartridge 10 may be configured to propel firearm projectile
100 (and/or each of a plurality of such firearm projectiles)
through air such that, when the firearm cartridge is fired
horizontally in air, the firearm projectile has a velocity after
traveling 36.6 meters (40 yards) that is at least 1.1 times, at
least 1.2 times, at least 1.3 times, at least 1.4 times, at least
1.5 times, at least 1.6 times, at least 1.7 times, at least 1.8
times, at least 1.9 times, at most 2 times, at most 1.95 times, at
most 1.85 times, at most 1.75 times, at most 1.65 times, at most
1.55 times, at most 1.45 times, at most 1.35 times, at most 1.25
times, and/or at most 1.15 times a velocity of a smooth firearm
projectile fired by an otherwise identical firearm cartridge in
which the smooth firearm projectile lacks turbulence-inducing
surface 120 when the otherwise identical firearm cartridge is fired
horizontally in air and after the smooth firearm projectile travels
36.6 meters (40 yards).
[0072] In some examples, such as when utilizing firearm projectiles
100 with diameter 102 of 2.54 mm (0.10 in.) or smaller, it may be
desirable that shot shell 14 be configured to propel the firearm
projectiles with a higher initial velocity relative to a shot shell
containing larger firearm projectiles. For example, because the
Reynolds number associated with the motion of firearm projectile
100 through air is proportional to both diameter 102 and the
velocity of the firearm projectile relative to the air, a reduction
in diameter 102 may motivate a corresponding increase in velocity
to maintain the Reynolds number within a desirable range.
Accordingly, shot shells 14 that contain comparatively small
firearm projectiles 100 (such as with diameter 102 of 2.54 mm or
smaller) may include a smaller payload 38 (e.g., a smaller total
mass of the payload) and/or a greater charge of propellant 22
relative to shot shells that contain comparatively large firearm
projectiles, thereby increasing the total acceleration imparted
upon the payload by the propellant.
[0073] FIG. 9 provides examples of methods 200 for forming firearm
ammunition such as firearm projectiles 100 with turbulence-inducing
surfaces 120 and/or firearm cartridges 10 containing the same
according to the present disclosure. The methods presented in FIG.
9 are not intended to be exhaustive or required for production of
all firearm projectiles 100 and/or firearm cartridges 10 according
to the present disclosure. Similarly, methods 200 may include
additional steps and/or substeps without departing from the scope
of the present disclosure. Unless a particular step must be
completed to enable a subsequent step to be performed, the examples
of steps shown and/or discussed in connection with FIG. 9 may be
performed in any suitable concurrent and/or sequential order. In
the following discussion, reference numerals for the previously
discussed turbulence-inducing surfaces 120, firearm projectiles
100, firearm cartridges 10 containing the same, and components
thereof are utilized to provide references to the structures shown
and discussed with respect to FIGS. 1-8 even though these reference
numerals are not shown in FIG. 9.
[0074] As shown in FIG. 9, a method 200 of manufacturing firearm
ammunition includes (such as may include and/or be firearm
projectile 100) includes providing, at 210, a base projectile that
is at least substantially spherical with a smooth exterior surface,
and forming, at 216, a turbulence-inducing surface (such as
turbulence-inducing surface 120) on the exterior surface of the
base projectile. Accordingly, method 200 includes forming a firearm
projectile (such as firearm projectile 100) that includes a
projectile body (such as projectile body 110) and the
turbulence-inducing surface (such as turbulence-inducing surface
120) such that the turbulence-inducing surface at least
substantially encloses the projectile body, covers the projectile
body, and/or forms the exterior surface of the projectile body.
[0075] The providing the base projectile at 210 may include
providing and/or producing the base projectile in any appropriate
manner. For example, the providing at 210 may include obtaining the
base projectile in the form of a smooth and/or nominally spherical
shot pellet. Alternatively, and as shown in FIG. 9, the providing
at 210 may include providing, at 212, a projectile precursor that
is not substantially spherical and/or not substantially smooth and
shaping, at 214, the projectile precursor into the substantially
spherical base projectile. In such an example, the projectile
precursor may take any appropriate shape and/or form, such as a
wire segment, an ovoid, an oblong sphere, and/or an oblate sphere.
Additionally or alternatively, in such an example, the shaping at
214 may be performed in any appropriate manner, such as by milling
the projectile precursor with an impact mill. In an example in
which the providing the base projectile at 210 includes producing
the base projectile, the producing may be performed in any
appropriate manner, such as via a casting process and/or via a
powder metallurgy process. As more specific examples, the producing
may include producing via a powder metallurgy process with or
without heating and/or sintering steps.
[0076] The forming the turbulence-inducing surface at 216 may be
performed in any appropriate manner. For example, the forming the
turbulence-inducing surface at 216 may include forming a plurality
of surface features (such as surface features 160) on the exterior
surface of the base projectile. As a more specific example, and as
shown in FIG. 9, the forming at 216 may include adding, at 218,
material to the exterior surface of the base projectile, such as by
applying a coating or other material to the exterior surface of the
base projectile. In such an example, the turbulence-inducing
surface may include and/or be the coating and/or other material.
Additionally or alternatively, and as further shown in FIG. 9, the
forming at 216 may include removing, at 220, material from the base
projectile. Additionally or alternatively, and as further shown in
FIG. 9, the forming at 216 may include deforming, at 222, the
exterior surface of the base projectile, such as via one or more
processes as disclosed herein and/or via a plastic deformation
process.
[0077] In some examples, the forming the turbulence-inducing
surface at 216 may include two or more of the adding material to
the exterior surface of the base projectile at 218, the removing
material from the base projectile at 220, and the deforming the
exterior surface of the base projectile at 222. For example, the
forming at 216 may include performing two or more of the adding at
218, the removing at 220, and the deforming at 222 sequentially. As
another example, the deforming at 222 additionally or alternatively
may be described as including the adding at 218 and/or the removing
at 220. Additionally or alternatively, and as shown in FIG. 9, the
forming the turbulence-inducing surface at 216 may include
chemically etching, at 224, the exterior surface of the base
projectile, and/or may include mechanically deforming, at 226, the
exterior surface of the base projectile. In an example in which the
forming at 216 includes the chemically etching at 224 and the
mechanically deforming at 226, the chemically etching at 224 may be
performed prior to and/or subsequent to the mechanically deforming
at 226.
[0078] In an example of the forming the turbulence-inducing surface
at 216 that includes the chemically etching the exterior surface of
the base projectile at 224, the chemically etching at 224 may be
performed in any appropriate manner sufficient to at least
partially form the turbulence-inducing surface. As examples, the
chemically etching at 224 may include the removing material from
the exterior surface of the base projectile at 220 and/or the
deforming the exterior surface of the base projectile at 222, such
as via preferentially etching one or more grain boundaries of the
exterior surface of the base projectile. The chemically etching at
224 may include etching the exterior surface of the base projectile
with any appropriate etchant, examples of which include an acid, a
strong acid, and hydrochloric acid. In such examples, the acid may
have any appropriate concentration by weight, examples of which
include at least 10%, at least 20%, at least 30%, at least 40%, at
most 50%, at most 45%, at most 35%, at most 25%, and/or at most
15%.
[0079] The chemically etching at 224 may include submerging the
base projectile in the etchant for an etching duration. As
examples, the etching duration may be at least 1 minute, at least 5
minutes, at least 10 minutes, at least 15 minutes, at least 20
minutes, at least 30 minutes, at least 60 minutes, at most 75
minutes, at most 45 minutes, at most 25 minutes, at most 17
minutes, at most 12 minutes, and/or at most 7 minutes. The etching
duration may be at least partially related to a degree and/or
quality of roughness formed on the exterior surface of the base
projectile. Additionally or alternatively, the chemically etching
at 224 may include etching for an etching duration that is
sufficient to produce a passivation layer on the exterior surface
of the base projectile, such as may restrict, inhibit, and/or
saturate further chemical etching of the exterior surface.
[0080] While the examples of the chemically etching at 224
described herein relate generally to examples in which the exterior
surface of the base projectile is dissolved by an acid, this is not
required to all examples of the chemically etching at 224, and it
is additionally within the scope of the present disclosure that the
chemically etching at 224 may include and/or be any appropriate
chemical process. As an example, the chemical etching at 224
additionally or alternatively may include oxidizing the exterior
surface of the base projectile, such as by heating the base
projectile in air. As another example, the chemical etching at 224
additionally or alternatively may include an electrolysis process
and/or an electroetching process.
[0081] An example of the turbulence-inducing surface formed via the
chemically etching at 224 may have any corresponding surface
features and/or characteristics. For example, the chemically
etching at 224 may produce an etched surface (such as etched
surface 132 as illustrated in FIGS. 3-4), such as via preferential
etching of grain boundaries exposed at or near the exterior surface
of the base projectile to form a plurality, network, and/or mosaic
of grooves and/or channels.
[0082] In an example of the forming the turbulence-inducing surface
at 216 that includes the mechanically deforming the exterior
surface of the base projectile at 226, the mechanically deforming
at 228 may be performed in any appropriate manner to at least
partially form the turbulence-inducing surface. As an example, the
mechanically deforming at 226 may include and/or be an example of
the deforming the exterior surface of the base projectile at
222.
[0083] The mechanically deforming the exterior surface of the base
projectile at 226 may include and/or be any appropriate process.
For example, the mechanically deforming at 226 may include
mechanically abrading the exterior surface of the base projectile
via a shear process, such as by rolling the base projectile
relative to an abrasive belt. In such an example, the mechanically
deforming at 226 may produce a mechanically abraded surface (such
as mechanically abraded surface 134 of FIGS. 3 and 5) that includes
a plurality of scratches. Mechanically abrading the exterior
surface of the base projectile via a shear process may include
and/or be an example of the removing material from the exterior
surface of the base projectile at 220 and/or the deforming the
exterior surface of the base projectile at 222. Stated differently,
mechanically abrading the exterior surface of the base projectile
may include scratching away material from the exterior surface
and/or redistributing material on the exterior surface.
[0084] As another example, the mechanically deforming the exterior
surface of the base projectile at 226 may include abrasively
blasting the exterior surface of the base projectile, such as by
propelling an abrasive medium toward the base projectile. As
examples, the abrasive medium may include air, water, sand, grit,
pellets, additional base projectiles, and/or firearm projectiles.
As more specific examples, the mechanically deforming at 226 may
include deforming the exterior surface of the base projectile with
a shot blasting apparatus and/or a shot peening apparatus.
Representative examples of shot blasting and/or shot peening
apparatuses may be produced by the Pangborn Group of Fairburn, Ga.,
U.S.A and/or by the Norican Group of Taastrup, Denmark. The
mechanically deforming at 226 may produce an abrasively blasted
surface (such as abrasively blasted surface 136 of FIGS. 3 and 6)
that includes a plurality of depressions (such as depressions 162),
such as crater-like depressions with raised rims.
[0085] Abrasively blasting the exterior surface of the base
projectile may include and/or be an example of the removing
material from the exterior surface of the base projectile at 220
and/or the deforming the exterior surface of the base projectile at
222. Stated differently, abrasively blasting the exterior surface
of the base projectile may include blasting away material from the
exterior surface and/or redistributing material on the exterior
surface.
[0086] As yet another example, the mechanically deforming the
exterior surface of the base projectile at 226 may include
mechanically roughening the exterior surface of the base projectile
via a repetitious mechanical roughening process, such as a tumbling
process, a rolling process, and/or a milling process. As more
specific examples, the repetitious mechanical roughening process
may include repeatedly colliding the base projectile with a hammer,
a grit, a pellet, a separate base projectile, and a firearm
projectile. Mechanically deforming the exterior surface of the base
projectile via a repetitious mechanical roughening process may
include and/or be an example of the removing material from the
exterior surface of the base projectile at 220 and/or the deforming
the exterior surface of the base projectile at 222. Stated
differently, a mechanical roughening process may include knocking
away material from the exterior surface and/or redistributing
material on the exterior surface.
[0087] With continued reference to FIG. 9, method 200 may include,
subsequent to the forming the turbulence-inducing surface at 216,
finishing, at 228, the turbulence-inducing surface. The finishing
at 228 may include any appropriate processes and/or steps, such as
for removing a byproduct of the forming at 216 from the
turbulence-inducing surface and/or for optimizing a material
property of the firearm projectile. As examples, and as shown in
FIG. 9, the finishing the turbulence-inducing surface at 228 may
include cleaning, at 230, the turbulence-inducing surface;
polishing, at 232, the turbulence-inducing surface; and/or
annealing, at 234, the turbulence-inducing surface.
[0088] As further shown in FIG. 9, method 200 may include,
subsequent to the forming the turbulence-inducing surface at 216,
assembling, at 236, a firearm cartridge (such as firearm cartridge
10) that includes the firearm projectile. As an example, the
firearm cartridge may be a shot shell (such as shot shell 150). In
such an example, the assembling the firearm cartridge at 236 may
include positioning a primer (such as primer 32) and/or a
propellant (such as propellant 22) within a casing (such as casing
18) of the firearm cartridge; positioning a wad (such as wad 31)
within the casing; and/or positioning a payload (such as payload
38) into a payload region (such as payload region 39) of the
firearm cartridge such that the wad at least substantially
separates the propellant and the payload. As discussed herein,
forming the turbulence-inducing surface on the firearm projectile
may enable the firearm projectile to travel with a reduced drag
coefficient relative to an otherwise identical firearm projectile
that lacks the turbulence-inducing surface. Accordingly, firearm
cartridges produced via methods 200 may include less propellant
and/or fewer firearm projectiles relative to conventional firearm
cartridges that include firearm projectiles without
turbulence-inducing surfaces while retaining performance metrics
(such as lethality per cartridge and/or lethality per firearm
projectile) similar to those of conventional firearm
cartridges.
[0089] As used herein, the term "and/or" placed between a first
entity and a second entity means one of (1) the first entity, (2)
the second entity, and (3) the first entity and the second entity.
Multiple entities listed with "and/or" should be construed in the
same manner, i.e., "one or more" of the entities so conjoined.
Other entities may optionally be present other than the entities
specifically identified by the "and/or" clause, whether related or
unrelated to those entities specifically identified. Thus, as a
non-limiting example, a reference to "A and/or B," when used in
conjunction with open-ended language such as "comprising" may
refer, in one embodiment, to A only (optionally including entities
other than B); in another embodiment, to B only (optionally
including entities other than A); in yet another embodiment, to
both A and B (optionally including other entities). These entities
may refer to elements, actions, structures, steps, operations,
values, and the like.
[0090] As used herein, the phrase "at least one," in reference to a
list of one or more entities should be understood to mean at least
one entity selected from any one or more of the entity in the list
of entities, but not necessarily including at least one of each and
every entity specifically listed within the list of entities and
not excluding any combinations of entities in the list of entities.
This definition also allows that entities may optionally be present
other than the entities specifically identified within the list of
entities to which the phrase "at least one" refers, whether related
or unrelated to those entities specifically identified. Thus, as a
non-limiting example, "at least one of A and B" (or, equivalently,
"at least one of A or B," or, equivalently "at least one of A
and/or B") may refer, in one embodiment, to at least one,
optionally including more than one, A, with no B present (and
optionally including entities other than B); in another embodiment,
to at least one, optionally including more than one, B, with no A
present (and optionally including entities other than A); in yet
another embodiment, to at least one, optionally including more than
one, A, and at least one, optionally including more than one, B
(and optionally including other entities). In other words, the
phrases "at least one," "one or more," and "and/or" are open-ended
expressions that are both conjunctive and disjunctive in operation.
For example, each of the expressions "at least one of A, B, and C,"
"at least one of A, B, or C," "one or more of A, B, and C," "one or
more of A, B, or C" and "A, B, and/or C" may mean A alone, B alone,
C alone, A and B together, A and C together, B and C together, A,
B, and C together, and optionally any of the above in combination
with at least one other entity.
[0091] As used herein, "at least substantially," when modifying a
degree or relationship, includes not only the recited "substantial"
degree or relationship, but also the full extent of the recited
degree or relationship. A substantial amount of a recited degree or
relationship may include at least 75% of the recited degree or
relationship. For example, an object that is at least substantially
formed from a material includes an object for which at least 75% of
the object is formed from the material and also includes an object
that is completely formed from the material. As another example, a
first length that is at least substantially as long as a second
length includes a first length that is at least 75% as long as the
second length and also includes a first length that is as long as
the second length.
[0092] As used herein, the phrase, "for example," the phrase, "as
an example," and/or simply the term "example," when used with
reference to one or more components, features, details, structures,
embodiments, and/or methods according to the present disclosure,
are intended to convey that the described component, feature,
detail, structure, embodiment, and/or method is an illustrative,
non-exclusive example of components, features, details, structures,
embodiments, and/or methods according to the present disclosure.
Thus, the described component, feature, detail, structure,
embodiment, and/or method is not intended to be limiting, required,
or exclusive/exhaustive; and other components, features, details,
structures, embodiments, and/or methods, including structurally
and/or functionally similar and/or equivalent components, features,
details, structures, embodiments, and/or methods, are also within
the scope of the present disclosure.
[0093] In the event that any patents, patent applications, or other
references are incorporated by reference herein and (1) define a
term in a manner that is inconsistent with and/or (2) are otherwise
inconsistent with, either the non-incorporated portion of the
present disclosure or any of the other incorporated references, the
non-incorporated portion of the present disclosure shall control,
and the term or incorporated disclosure therein shall only control
with respect to the reference in which the term is defined and/or
the incorporated disclosure was present originally.
[0094] As used herein the terms "adapted" and "configured" mean
that the element, component, or other subject matter is designed
and/or intended to perform a given function. Thus, the use of the
terms "adapted" and "configured" should not be construed to mean
that a given element, component, or other subject matter is simply
"capable of" performing a given function but that the element,
component, and/or other subject matter is specifically selected,
created, implemented, utilized, programmed, and/or designed for the
purpose of performing the function.
[0095] It is also within the scope of the present disclosure that
elements, components, and/or other recited subject matter that is
recited as being adapted to perform a particular function may
additionally or alternatively be described as being configured to
perform that function, and vice versa.
[0096] Examples of firearm projectiles, firearm cartridges
containing the same, and associated methods are presented in the
following enumerated paragraphs.
[0097] A1. A firearm projectile, comprising:
[0098] a projectile body; and
[0099] a turbulence-inducing surface at least substantially
enclosing the projectile body.
[0100] A1.1. The firearm projectile of paragraph A1, wherein the
firearm projectile is at least substantially spherical.
[0101] A1.2. The firearm projectile of any of paragraphs A1-A1.1,
wherein the firearm projectile is a shot pellet.
[0102] A1.3. The firearm projectile of any of paragraphs A1-A1.2,
wherein the turbulence-inducing surface is configured to induce
turbulence in a boundary layer of air adjacent to the firearm
projectile when the firearm projectile travels through air with a
Reynolds number that is one or more of less than 300,000, less than
200,000, less than 100,000, and greater than 10,000.
[0103] A1.4. The firearm projectile of any of paragraphs A1-A1.3,
wherein the turbulence-inducing surface is configured to induce a
drag crisis in a drag coefficient of the firearm projectile when
the firearm projectile travels through air with a critical Reynolds
number that is one or more of less than 300,000, less than 200,000,
less than 100,000, and greater than 10,000.
[0104] A1.5. The firearm projectile of any of paragraphs A1-A1.4,
wherein the firearm projectile has a diameter that is one or more
of at least 1 millimeter (mm), at least 1.5 mm, at least 2 mm, at
least 2.5 mm, at least 3 mm, at least 3.5 mm, at least 4 mm, at
least 4.5 mm, at least 5 mm, at least 6 mm, at least 7 mm, at least
8 mm, at least 9 mm, at least 10 mm, at least 15 mm, at least 20
mm, at most 25 mm, at most 17 mm, at most 12 mm, at most 9.5 mm, at
most 8.5 mm, at most 7.5 mm, at most 6.5 mm, at most 5.5 mm, at
most 4.7 mm, at most 4.2 mm, at most 3.7 mm, at most 3.2 mm, at
most 2.7 mm, at most 2.2 mm, at most 1.7 mm, and at most 1.2
mm.
[0105] A1.6. The firearm projectile of any of paragraphs A1-A1.5,
wherein the firearm projectile is formed of one or more of lead,
steel, iron, copper, zinc, nickel, tungsten, bismuth, tin, cobalt,
aluminum, steel, bronze, manganese, and/or alloys and/or mixtures
thereof.
[0106] A1.7. The firearm projectile of any of paragraphs A1-A1.6,
wherein the firearm projectile has a density of one or more of at
least 6 grams per cubic centimeter (g/cc), at least 6.5 g/cc, at
least 7 g/cc, at least 7.5 g/cc, at least 8 g/cc, at least 8.5
g/cc, at least 9.0 g/cc, at least 9.5 g/cc, at most 10 g/cc, at
least 10.5 g/cc, at least 11 g/cc, at least 11.5 g/cc, at least 12
g/cc, at least 13 g/cc, at least 13.5 g/cc, at least 14 g/cc, at
least 14.5 g/cc, at least 15 g/cc, at most 16 g/cc, at most 15
g/cc, at most 14 g/cc, at most 13 g/cc, at most 12 g/cc, at most
11.5 g/cc, at most 11 g/cc, at most 10 g/cc, at most 9.5 g/cc, at
most 9 g/cc, at most 8.5 g/cc, at most 8.0 g/cc, at most 7.5 g/cc,
and at most 7.0 g/cc.
[0107] A1.8. The firearm projectile of any of paragraphs A1-A1.7,
wherein the projectile body and the turbulence-inducing surface are
formed of the same material.
[0108] A1.9. The firearm projectile of any of paragraphs A1-A1.8,
wherein the turbulence-inducing surface is integral with the
projectile body.
[0109] A2.1. The firearm projectile of any of paragraphs A1-A1.9,
wherein when the firearm projectile traveling through air has a
Reynolds number that is less than 300,000, the firearm projectile
has a drag coefficient that is less than 0.35.
[0110] A2.2. The firearm projectile of any of paragraphs A1-A2.1,
wherein when the firearm projectile traveling through air has a
Reynolds number that is less than a maximum ballistic Reynolds
number and greater than a minimum ballistic Reynolds number, the
firearm projectile has a drag coefficient that is less than about
0.35.
[0111] A2.3. The firearm projectile of any of paragraphs A1-A2.2,
wherein the firearm projectile has a drag coefficient that is at
least substantially constant, optionally constant to within 50%,
further optionally to within 20%, when traveling through air with a
Reynolds number that is less than a/the maximum ballistic Reynolds
number and greater than a/the minimum ballistic Reynolds
number.
[0112] A2.4. The firearm projectile of any of paragraphs A2.2-A2.3,
wherein the firearm projectile is a BBB shot pellet with a diameter
of 4.83 mm (0.19 inches (in.)), wherein the maximum ballistic
Reynolds number is about 166,000, and wherein the minimum ballistic
Reynolds number is about 128,000.
[0113] A2.5. The firearm projectile of any of paragraphs A2.2-A2.3,
wherein the firearm projectile is a BB shot pellet with a diameter
of 4.57 mm (0.18 in.), wherein the maximum ballistic Reynolds
number is about 157,000, and wherein the minimum ballistic Reynolds
number is about 119,000.
[0114] A2.6. The firearm projectile of any of paragraphs A2.2-A2.3,
wherein the firearm projectile is a B shot pellet with a diameter
of 4.32 mm (0.17 in.), wherein the maximum ballistic Reynolds
number is about 148,000, and wherein the minimum ballistic Reynolds
number is about 112,000.
[0115] A2.7. The firearm projectile of any of paragraphs A2.2-A2.3,
wherein the firearm projectile is a #1 shot pellet with a diameter
of 4.06 mm (0.16 in.), wherein the maximum ballistic Reynolds
number is about 140,000, and wherein the minimum ballistic Reynolds
number is about 104,000.
[0116] A2.8. The firearm projectile of any of paragraphs A2.2-A2.3,
wherein the firearm projectile is a #2 shot pellet with a diameter
of 3.81 mm (0.15 in.), wherein the maximum ballistic Reynolds
number is about 131,000, and wherein the minimum ballistic Reynolds
number is about 96,800.
[0117] A2.9. The firearm projectile of any of paragraphs A2.2-A2.3,
wherein the firearm projectile is a #3 shot pellet with a diameter
of 3.56 mm (0.14 in.), wherein the maximum ballistic Reynolds
number is about 122,000, and wherein the minimum ballistic Reynolds
number is about 89,200.
[0118] A2.10. The firearm projectile of any of paragraphs
A2.2-A2.3, wherein the firearm projectile is a #4 shot pellet with
a diameter of 3.30 mm (0.13 in.), wherein the maximum ballistic
Reynolds number is about 114,000, and wherein the minimum ballistic
Reynolds number is about 81,700.
[0119] A2.11. The firearm projectile of any of paragraphs
A2.2-A2.3, wherein the firearm projectile is a #5 shot pellet with
a diameter of 3.05 mm (0.12 in.), wherein the maximum ballistic
Reynolds number is about 105,000, and wherein the minimum ballistic
Reynolds number is about 74,200.
[0120] A2.12. The firearm projectile of any of paragraphs
A2.2-A2.3, wherein the firearm projectile is a #6 shot pellet with
a diameter of 2.79 mm (0.11 in.), wherein the maximum ballistic
Reynolds number is about 96,000, and wherein the minimum ballistic
Reynolds number is about 66,800.
[0121] A2.13. The firearm projectile of any of paragraphs
A2.2-A2.3, wherein the firearm projectile is a #7 shot pellet with
a diameter of 2.54 mm (0.10 in.), wherein the maximum ballistic
Reynolds number is about 88,000, and wherein the minimum ballistic
Reynolds number is about 59,500.
[0122] A2.14. The firearm projectile of any of paragraphs
A2.2-A2.3, wherein the firearm projectile is a #71/2 shot pellet
with a diameter of 2.41 mm (0.095 in.), wherein the maximum
ballistic Reynolds number is about 83,000, and wherein the minimum
ballistic Reynolds number is about 55,800.
[0123] A2.15. The firearm projectile of any of paragraphs
A2.2-A2.3, wherein the firearm projectile is a #8 shot pellet with
a diameter of 2.29 mm (0.090 in.), wherein the maximum ballistic
Reynolds number is about 79,000, and wherein the minimum ballistic
Reynolds number is about 52,200.
[0124] A2.16. The firearm projectile of any of paragraphs A1-A2.15,
wherein the firearm projectile has a drag coefficient when
traveling through air at a given velocity that is less than a drag
coefficient of a smooth spherical projectile of the same mass and
material composition as the firearm projectile and that lacks the
turbulence-inducing surface when the smooth spherical projectile
travels through air with the given velocity.
[0125] A2.17. The firearm projectile of paragraph A2.16, wherein,
when traveling through air at the given velocity, the firearm
projectile has a drag coefficient that is one or more of at least
0.1 times, at least 0.25 times, at least 0.35 times, at least 0.45
times, at least 0.55 times, at least 0.65 times, at least 0.75
times, at least 0.85 times, at most 0.9 times, at most 0.8 times,
at most 0.7 times, at most 0.6 times, at most 0.5 times, at most
0.4 times, at most 0.3 times, and at most 0.2 times a drag
coefficient of the smooth spherical projectile that lacks the
turbulence-inducing surface.
[0126] A3.1. The firearm projectile of any of paragraphs A1-A2.17,
wherein the turbulence-inducing surface consists of a plurality of
non-overlapping surface loci; wherein each surface locus of the
plurality of surface loci has a corresponding locus radius, as
measured between the surface locus and a center point of the
projectile body; wherein the firearm projectile has a reference
radius; wherein each surface locus of the plurality of surface loci
further has a corresponding radial deviation that is equal to the
corresponding locus radius minus the reference radius; and wherein
the firearm projectile is characterized by a roughness metric that
is based, at least in part, on the set of corresponding radial
deviations of the plurality of surface loci.
[0127] A3.2. The firearm projectile of paragraph A3.1, wherein the
corresponding locus radius of each surface locus is measured
between the center point of the projectile body and a center point
of the surface locus.
[0128] A3.3. The firearm projectile of any of paragraphs A3.1-A3.2,
wherein the reference radius is equal to the arithmetic mean of the
corresponding locus radii of the plurality of surface loci.
[0129] A3.4. The firearm projectile of any of paragraphs A3.1-A3.3,
wherein the reference radius is equal to a radius of the projectile
body.
[0130] A3.5. The firearm projectile of any of paragraphs A3.1-A3.4,
wherein the reference radius is equal to a maximum radius of the
firearm projectile.
[0131] A3.6. The firearm projectile of any of paragraphs A3.1-A3.4,
wherein the reference radius is equal to a minimum radius of the
firearm projectile.
[0132] A3.7. The firearm projectile of any of paragraphs A3.1-A3.6,
wherein the roughness metric includes an arithmetical mean
deviation, defined as the arithmetic mean of the absolute values of
the set of corresponding radial deviations of the plurality of
surface loci.
[0133] A3.8. The firearm projectile of any of paragraphs A3.1-A3.7,
wherein the roughness metric includes a root mean squared
deviation, defined as the square root of the arithmetic mean of the
squares of the set of corresponding radial deviations of the
plurality of surface loci.
[0134] A3.9. The firearm projectile of any of paragraphs A3.1-A3.8,
wherein the roughness metric includes a normalized central moment
of order n, wherein n is an integer that is greater than 2, wherein
the normalized central moment of order n is defined as the
arithmetic mean of the nth power of each of the corresponding
radial deviations of the plurality of surface loci divided by the
nth power of a/the root mean squared deviation of the corresponding
radial deviations of the plurality of surface loci.
[0135] A3.10. The firearm projectile of paragraph A3.9, wherein n
is equal to 3, and wherein the normalized central moment is
negative.
[0136] A3.11. The firearm projectile of paragraph A3.9, wherein n
is equal to 3, and wherein the normalized central moment is
positive.
[0137] A3.12. The firearm projectile of any of paragraphs
A3.1-A3.11, wherein the roughness metric includes a maximum
positive deviation, defined as the maximum value of the set of
corresponding radial deviations of the plurality of surface
loci.
[0138] A3.13. The firearm projectile of any of paragraphs
A3.1-A3.12, wherein the roughness metric includes a maximum
negative deviation, defined as the minimum value of the set of
corresponding radial deviations of the plurality of surface
loci.
[0139] A3.14. The firearm projectile of any of paragraphs
A3.1-A3.13, wherein the roughness metric includes a radial range,
defined as the absolute difference between a/the maximum positive
deviation and a/the maximum negative deviation.
[0140] A3.15. The firearm projectile of any of paragraphs
A3.1-A3.14, wherein the roughness metric is at least partially
based upon a characteristic roughness depth of the
turbulence-inducing surface.
[0141] A3.16. The firearm projectile of paragraph A3.15, wherein
the characteristic roughness depth is one of a sand roughness,
an/the arithmetical mean deviation, a/the root mean squared
deviation, and a/the normalized central moment of order n.
[0142] A3.17. The firearm projectile of any of paragraphs
A3.15-A3.16, wherein the characteristic roughness depth is one or
more of at least 1 micrometer (.mu.m), at least 3 .mu.m, at least 5
.mu.m, at least 30 .mu.m, at least 50 .mu.m, at least 100 .mu.m, at
least 300 .mu.m, at least 500 .mu.m, at least 1 mm, at most 2 mm,
at most 700 .mu.m, at most 200 .mu.m, at most 70 .mu.m, at most 20
.mu.m, at most 7 .mu.m, and at most 2 .mu.m.
[0143] A3.18. The firearm projectile of any of paragraphs
A3.15-A3.17, wherein the roughness metric includes a relative
roughness ratio, defined as the ratio of the characteristic
roughness depth of the turbulence-inducing surface to a diameter of
the firearm projectile.
[0144] A3.19. The firearm projectile of paragraph A3.18, wherein
the absolute value of the relative roughness ratio is one or more
of at least 0.00001, at least 0.00003, at least 0.00005, at least
0.0001, at least 0.0003, at least 0.0005, at least 0.001, at least
0.003, at least 0.005, at least 0.01, at least 0.03, at least 0.05,
at most 0.1, at most 0.07, at most 0.035, at most 0.02, at most
0.007, at most 0.002, at most 0.0007, at most 0.0002, at most
0.00007, and at most 0.00002.
[0145] A3.20. The firearm projectile of any of paragraphs
A3.1-A3.19, wherein each surface locus of the plurality of surface
loci occupies substantially the same solid angle.
[0146] A3.21. The firearm projectile of any of paragraphs
A3.1-A3.20, wherein each surface locus of the plurality of surface
loci occupies a solid angle that one or more of:
[0147] (i) less than 0.1 steradians;
[0148] (ii) less than 0.01 steradians;
[0149] (iii) less than 0.001 steradians;
[0150] (iv) less than 0.0001 steradians; and
[0151] (v) greater than 0 steradians.
[0152] A3.22. The firearm projectile of any of paragraphs
A3.1-A3.21, wherein each surface locus of the plurality of surface
loci occupies the same surface area.
[0153] A3.23. The firearm projectile of any of paragraphs
A3.1-A3.22, wherein each surface locus of the plurality of surface
loci occupies a surface area that is one or more of:
[0154] (i) less than 1% of a total surface area of the
turbulence-inducing surface;
[0155] (ii) less than 0.1% of the total surface area of the
turbulence-inducing surface;
[0156] (iii) less than 0.01% of the total surface area of the
turbulence-inducing surface;
[0157] (iv) less than 0.001% of the total surface area of the
turbulence-inducing surface; and
[0158] (v) greater than 0% of the total surface area of the
turbulence-inducing surface.
[0159] A3.24. The firearm projectile of any of paragraphs
A3.1-A3.23, wherein the plurality of surface loci includes one or
more of:
[0160] (i) at least 100 surface loci;
[0161] (ii) at least 1000 surface loci;
[0162] (iii) at least 10,000 surface loci;
[0163] (iv) at least 100,000 surface loci; and
[0164] (v) at most 10,000,000 surface loci.
[0165] A4.1. The firearm projectile of any of paragraphs A1-A3.24,
wherein the turbulence-inducing surface includes a plurality of
surface features.
[0166] A4.2. The firearm projectile of paragraph A4.1, wherein the
plurality of surface features includes one or more depressions.
[0167] A4.3. The firearm projectile of paragraph A4.2, wherein each
depression has a corresponding depression depth, defined as an
absolute difference between a minimum radius of the firearm
projectile within the depression and a/the reference radius of the
firearm projectile, that is one or more of at least 1 .mu.m, at
least 3 .mu.m, at least 5 .mu.m, at least 30 .mu.m, at least 50
.mu.m, at least 100 .mu.m, at least 300 .mu.m, at least 500 .mu.m,
at least 1 mm, at most 2 mm, at most 700 .mu.m, at most 200 .mu.m,
at most 70 .mu.m, at most 20 .mu.m, at most 7 .mu.m, and at most 2
.mu.m.
[0168] A4.4. The firearm projectile of any of paragraphs A4.1-A4.3,
wherein the plurality of surface features includes one or more
protrusions.
[0169] A4.5. The firearm projectile of paragraph A4.4, wherein each
protrusion has a corresponding protrusion height, defined as an
absolute difference between a maximum radius of the firearm
projectile within the protrusion and a/the reference radius of the
firearm projectile, that is one or more of at least 1 .mu.m, at
least 3 .mu.m, at least 5 .mu.m, at least 30 .mu.m, at least 50
.mu.m, at least 100 .mu.m, at least 300 .mu.m, at least 500 .mu.m,
at least 1 mm, at most 2 mm, at most 700 .mu.m, at most 200 .mu.m,
at most 70 .mu.m, at most 20 .mu.m, at most 7 .mu.m, and at most 2
.mu.m.
[0170] A4.6. The firearm projectile of any of paragraphs A4.1-4.5,
wherein the plurality of surface features includes one or more
localized surface features.
[0171] A4.7. The firearm projectile of paragraph A4.6, wherein each
localized surface feature includes at least one of a/the
depression, an indentation, a crater, a dimple, a/the protrusion, a
bump, and a pimple.
[0172] A4.8. The firearm projectile of paragraph A4.7, wherein at
least one localized surface feature includes a depression that is
at least substantially surrounded by a raised rim.
[0173] A4.9. The firearm projectile of any of paragraphs A4.1-A4.8,
wherein the plurality of surface features includes one or more
elongate surface features.
[0174] A4.10. The firearm projectile of paragraph A4.9, wherein
each elongate surface feature includes at least one of a ridge, an
edge, a channel, a groove, and a scratch.
[0175] A4.11. The firearm projectile of any of paragraphs
A4.9-A4.10, wherein two or more of the elongate surface features
are randomly oriented with respect to one another.
[0176] A4.12. The firearm projectile of any of paragraphs
A4.9-A4.11, wherein two or more of the elongate surface features
are at least substantially parallel with respect to one
another.
[0177] A4.13. The firearm projectile of any of paragraphs
A4.1-A4.12, wherein the turbulence-inducing surface includes a
first surface feature superimposed upon a second surface feature,
wherein each of the first surface feature and the second surface
feature is chosen from a list consisting of a dimple, a depression,
a recess, a channel, a groove, a ridge, a raised rim, a protrusion,
a pimple, a bump, and a facet.
[0178] A4.14. The firearm projectile of any of paragraphs A1-A4.13,
wherein the turbulence-inducing surface includes a polyhedral
surface.
[0179] A4.15. The firearm projectile of paragraph A4.14, wherein
the polyhedral surface includes one or more substantially flat
facets.
[0180] B1. A firearm cartridge, comprising:
[0181] a casing that defines an internal volume;
[0182] a propellant disposed in the internal volume;
[0183] a primer disposed in the internal volume and configured to
ignite the propellant; the firearm projectile of any of paragraphs
A1-A4.15 at least partially received in the casing.
[0184] B1.1. The firearm cartridge of paragraph B1, wherein at
least one of:
[0185] the firearm projectile is a shot pellet, and the firearm
cartridge is a shot shell; and
[0186] the firearm projectile is a shot pellet, and the firearm
cartridge is a shot shell containing a plurality of the firearm
projectiles.
[0187] B1.2. The firearm cartridge of any of paragraphs B1-B1.1,
wherein the firearm cartridge is configured to propel the firearm
projectile with a muzzle velocity that is one or more of at least
300 meters per second (m/s) (984 feet per second (ft/s)), at least
350 m/s (1,148 ft/s), at least 400 m/s (1,312 ft/s), at least 450
m/s (1,476 ft/s), at least 500 m/s (1,640 ft/s), at least 550 m/s
(1,804 ft/s), at most 600 m/s (1,969 ft/s), at most 575 m/s (1,886
ft/s), at most 525 m/s (1,722 ft/s), at most 475 m/s (1,558 ft/s),
at most 425 m/s (1,394 ft/s), at most 375 m/s (1,230 ft/s), and at
most 325 m/s (1,066 ft/s).
[0188] B1.3. The firearm cartridge of any of paragraphs B1-B1.2,
wherein the firearm cartridge is configured to propel the firearm
projectile through air with an initial Reynolds number of one or
more of at least 70,000, at least 80,000, at least 90,000, at least
100,000, at least 110,000, at least 120,000, at least 130,000, at
least 140,000, at least 150,000, at least 160,000, at least
170,000, at least 180,000, at least 190,000, at most 200,000, at
most 195,000, at most 185,000, at most 175,000, at most 165,000, at
most 155,000, at most 145,000, at most 135,000, at most 125,000, at
most 115,000, at most 95,000, at most 85,000, and at most
75,000.
[0189] B1.4. The firearm cartridge of any of paragraphs B1-B1.3,
wherein the firearm cartridge is configured to propel the firearm
projectile through air such that, when the firearm cartridge is
fired horizontally in air, the firearm projectile has a velocity
after traveling 36.6 meters (40 yards) that is one or more of at
least 1.1 times, at least 1.2 times, at least 1.3 times, at least
1.4 times, at least 1.5 times, at least 1.6 times, at least 1.7
times, at least 1.8 times, at least 1.9 times, at most 2 times, at
most 1.95 times, at most 1.85 times, at most 1.75 times, at most
1.65 times, at most 1.55 times, at most 1.45 times, at most 1.35
times, at most 1.25 times, and at most 1.15 times a velocity of a
smooth firearm projectile fired by an otherwise identical firearm
cartridge in which the smooth firearm projectile lacks the
turbulence-inducing surface when the otherwise identical firearm
cartridge is fired horizontally in air and after the smooth firearm
projectile travels 36.6 meters (40 yards).
[0190] C1. A method of manufacturing firearm ammunition, the method
comprising: [0191] providing a base projectile that is at least
substantially spherical, wherein the base projectile includes a
smooth exterior surface; and [0192] forming a turbulence-inducing
surface on the exterior surface of the base projectile;
[0193] wherein the firearm ammunition includes a firearm projectile
with a projectile body and the turbulence-inducing surface, and
wherein the turbulence-inducing surface at least substantially
encloses the projectile body.
[0194] C1.1. The method of paragraph C1, wherein the providing the
base projectile includes providing a smooth shot pellet.
[0195] C1.2. The method of paragraph C1, wherein the providing the
base projectile includes providing a projectile precursor that is
not substantially spherical and shaping the projectile precursor
into the base projectile that is at least substantially
spherical.
[0196] C1.2.1. The method of paragraph C1.2, wherein the projectile
precursor does not have a smooth exterior surface, and further
wherein the providing the base projectile includes forming the base
projectile from the projectile precursor.
[0197] C1.3. The method of paragraph C1.2 or paragraph C1.2.1,
wherein the projectile precursor includes one or more of a wire
segment, an ovoid, an oblong sphere, and an oblate sphere.
[0198] C1.4. The method of any of paragraphs C1.2-C1.3, wherein the
shaping includes milling the projectile precursor with an impact
mill.
[0199] C1.5. The method of any of paragraphs C1-C1.4, wherein the
providing the base projectile includes forming the base projectile
via a casting process.
[0200] C1.6. The method of any of paragraphs C1-C1.5, wherein the
providing the base projectile includes forming the base projectile
via a powder metallurgy process.
[0201] C1.7. The method of any of paragraphs C1-C1.6, wherein the
firearm projectile is the firearm projectile of any of paragraphs
A1-A4.15.
[0202] C2.1. The method of any of paragraphs C1-C1.7, wherein the
forming the turbulence-inducing surface includes adding material to
the exterior surface of the base projectile.
[0203] C2.2. The method of paragraph C2.1, wherein the forming the
turbulence-inducing surface includes applying a coating to the
exterior surface of the base projectile.
[0204] C2.3. The method of any of paragraphs C1-C2.2, wherein the
forming the turbulence-inducing surface includes removing material
from the exterior surface of the base projectile.
[0205] C2.4. The method of any of paragraphs C1-C2.3, wherein the
forming the turbulence-inducing surface includes deforming the
exterior surface of the base projectile.
[0206] C2.5. The method of any of paragraphs C1-C2.4, wherein the
forming the turbulence-inducing surface includes chemically etching
the exterior surface of the base projectile.
[0207] C2.6. The method of paragraph C2.5, wherein the chemically
etching includes preferentially etching one or more grain
boundaries of the exterior surface of the base projectile.
[0208] C2.7. The method of any of paragraphs C2.5-C2.6, wherein the
chemically etching includes etching the exterior surface of the
base projectile with an etchant.
[0209] C2.8. The method of paragraph C2.7, wherein the etchant
includes one or more of an acid, a strong acid, and hydrochloric
acid.
[0210] C2.9. The method of paragraph C2.8, wherein the acid has a
concentration by weight that is one or more of at least 10%, at
least 20%, at least 30%, at least 40%, at most 50%, at most 45%, at
most 35%, at most 25%, and at most 15%.
[0211] C2.10. The method of any of paragraphs C2.7-C2.9, wherein
the chemically etching includes submerging the base projectile in
the etchant for an etching duration, wherein the etching duration
is one or more of at least 1 minute, at least 5 minutes, at least
10 minutes, at least 15 minutes, at least 20 minutes, at least 30
minutes, at least 60 minutes, at most 75 minutes, at most 45
minutes, at most 25 minutes, at most 17 minutes, at most 12
minutes, and at most 7 minutes.
[0212] C2.11. The method of any of paragraphs C2.5-C2.10, wherein
the chemically etching includes forming a passivation layer on the
exterior surface of the base projectile.
[0213] C2.12. The method of any of paragraphs C2.5-C2.11, wherein
the chemically etching includes one or more of oxidizing the
exterior surface of the base projectile, performing an electrolysis
process, and performing an electroetching process.
[0214] C2.13. The method of any of paragraphs C1-C2.12, wherein the
forming the turbulence-inducing surface includes mechanically
deforming the exterior surface of the base projectile.
[0215] C2.14. The method of paragraph C2.13, wherein the
mechanically deforming includes mechanically abrading the exterior
surface of the base projectile via a shear process.
[0216] C2.15. The method of paragraph C2.14, wherein the
mechanically abrading the exterior surface includes rolling the
base projectile relative to an abrasive belt.
[0217] C2.16. The method of any of paragraphs C2.13-C2.15, wherein
the mechanically deforming includes abrasively blasting the
exterior surface of the base projectile.
[0218] C2.17. The method of paragraph C2.16, wherein the abrasively
blasting includes propelling an abrasive medium toward the base
projectile.
[0219] C2.18. The method of paragraph C2.17, wherein the abrasive
medium includes one or more of air, water, sand, grit, pellets,
separate base projectiles, and firearm projectiles.
[0220] C2.19. The method of any of paragraphs C2.13-C2.18, wherein
the mechanically deforming includes mechanically roughening the
exterior surface of the base projectile via a repetitious
mechanical roughening process.
[0221] C2.20. The method of paragraph C2.19, wherein the
repetitious mechanical roughening process includes one or more of a
tumbling process, a rolling process, and a milling process.
[0222] C2.21. The method of any of paragraphs C2.19-C2.20, wherein
the repetitious mechanical roughening process includes repeatedly
colliding the base projectile with one or more of a hammer, a grit,
a pellet, a separate base projectile, and a firearm projectile.
[0223] C2.22. The method of any of paragraphs C1-C2.21, when
dependent from paragraphs C2.5 and C2.13, wherein the forming the
turbulence-inducing surface includes the chemically etching the
exterior surface of the base projectile subsequent to the
mechanically deforming the exterior surface of the base
projectile.
[0224] C2.23. The method of any of paragraphs C1-C2.21, when
dependent from paragraphs C2.5 and C2.13, wherein the forming the
turbulence-inducing surface includes the chemically etching the
exterior surface of the base projectile prior to the mechanically
deforming the exterior surface of the base projectile.
[0225] C3.1. The method of any of paragraphs C1-C2.23, further
comprising, subsequent to the forming the turbulence-inducing
surface, finishing the turbulence-inducing surface, wherein the
finishing includes one or more of:
[0226] (i) cleaning the turbulence-inducing surface;
[0227] (ii) polishing the turbulence-inducing surface; and
[0228] (iii) annealing the turbulence-inducing surface.
[0229] C4.1. The method of any of paragraphs C1-C3.1, further
comprising, subsequent to the forming the turbulence-inducing
surface, assembling a firearm cartridge that includes the firearm
projectile.
[0230] C4.2. The method of paragraph C4.1, wherein the assembling
the firearm cartridge includes one or more of:
[0231] (i) positioning one or more of a primer and a propellant
within a casing of the firearm cartridge;
[0232] (ii) positioning a wad with the casing of the firearm
cartridge; and
[0233] (iii) positioning a payload that includes at least one
firearm projectile into a payload region of the firearm cartridge
such that the wad at least substantially separates the propellant
and the payload.
[0234] C4.3. The method of any of paragraphs C4.1-C4.2, wherein the
firearm cartridge is the firearm cartridge of any of paragraphs
B1-B1.4.
INDUSTRIAL APPLICABILITY
[0235] The firearm projectiles, firearm cartridges, and methods
disclosed herein are applicable to the firearm industry.
[0236] It is believed that the disclosure set forth above
encompasses multiple distinct inventions with independent utility.
While each of these inventions has been disclosed in its preferred
form, the specific embodiments thereof as disclosed and illustrated
herein are not to be considered in a limiting sense as numerous
variations are possible. The subject matter of the inventions
includes all novel and non-obvious combinations and subcombinations
of the various elements, features, functions and/or properties
disclosed herein. Similarly, where the claims recite "a" or "a
first" element or the equivalent thereof, such claims should be
understood to include incorporation of one or more such elements,
neither requiring nor excluding two or more such elements.
[0237] It is believed that the following claims particularly point
out certain combinations and subcombinations that are directed to
one of the disclosed inventions and are novel and non-obvious.
Inventions embodied in other combinations and subcombinations of
features, functions, elements, and/or properties may be claimed
through amendment of the present claims or presentation of new
claims in this or a related application. Such amended or new
claims, whether they are directed to a different invention or
directed to the same invention, whether different, broader,
narrower, or equal in scope to the original claims, are also
regarded as included within the subject matter of the inventions of
the present disclosure.
* * * * *