U.S. patent application number 16/872019 was filed with the patent office on 2021-11-11 for enhanced castable frangible breaching round.
The applicant listed for this patent is Rocky Mountain Scientific Laboratory, LLC. Invention is credited to Jon Kosak, Robert R. Nellums, Travis Swanson, Kristina Wikstrom.
Application Number | 20210348900 16/872019 |
Document ID | / |
Family ID | 1000005926006 |
Filed Date | 2021-11-11 |
United States Patent
Application |
20210348900 |
Kind Code |
A1 |
Swanson; Travis ; et
al. |
November 11, 2021 |
Enhanced Castable Frangible Breaching Round
Abstract
An enhanced breaching round and techniques for manufacturing
such are provided. A breaching round includes a case defining a
volume, a propellant disposed in the volume of the case, and a
projectile coupled to the case. The projectile may include a body
disposed at least partially within the case and configured to
enclose the propellant within the volume of the case. The body may
be formed of a castable eutectic mixture configured to be melted
and cast, wherein the body is configured to break into a plurality
of fragments upon impact with a target. A cavity may be disposed
between the proximal end and the distal end of the body, and a
reactive material disposed in the cavity, the reactive material
comprising at least one oxidizer and at least one fuel.
Inventors: |
Swanson; Travis; (Littleton,
CO) ; Kosak; Jon; (Littleton, CO) ; Nellums;
Robert R.; (Spring Hill, TN) ; Wikstrom;
Kristina; (Littleton, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rocky Mountain Scientific Laboratory, LLC |
Littleton |
CO |
US |
|
|
Family ID: |
1000005926006 |
Appl. No.: |
16/872019 |
Filed: |
May 11, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F42B 12/44 20130101;
F42B 5/145 20130101 |
International
Class: |
F42B 12/44 20060101
F42B012/44; F42B 5/145 20060101 F42B005/145 |
Claims
1. A breaching round comprising: a case defining a volume; a
propellant disposed in the volume of the case; and a projectile
coupled to the case, wherein the projectile comprises: a body
further comprising a base disposed at a distal end of the body and
a nose disposed at a proximal end of the body, wherein the base of
the body is disposed at least partially within the case and
configured to enclose the propellant within the volume of the case,
wherein a longitudinal axis of the body is defined by an axis
between the distal end and the proximal end, wherein the body is
formed of a castable eutectic mixture, the castable eutectic
mixture configured to be melted and cast, wherein the body is
configured to break into a plurality of fragments upon impact with
a target; a cavity disposed between the proximal end and the distal
end of the body; and a reactive material disposed in the cavity,
the reactive material comprising at least one oxidizer and at least
one fuel.
2. The breaching round of claim 1, wherein the reactive material is
formulated without a binder.
3. The breaching round of claim 1, wherein the cavity is disposed
in at least one of the nose of the body or the base of the
body.
4. The breaching round of claim 1, wherein the at least one
oxidizer includes at least one oxidizer selected from the group
consisting of ammonium perchlorate, ammonium nitrate, potassium
nitrate, potassium perchlorate, potassium chlorate, lithium
perchlorate, ceric ammonium nitrate, and mixtures thereof.
5. The breaching round of claim 4, wherein the reactive material is
at least one of: a) 0 to 55% ammonium perchlorate by mass, wherein
the reactive material comprises a plurality of granules of ammonium
perchlorate that range in size from 40 to 400 mesh; b) 0 to 55%
ammonium nitrate by mass, wherein the reactive material comprises a
plurality of granules of ammonium nitrate that range in size from
40 to 400 mesh; c) 0 to 45% potassium nitrate by mass, wherein the
reactive material comprises a plurality of granules of potassium
nitrate that range in size from 40 to 400 mesh; d) 0 to 50%
potassium perchlorate by mass, wherein the reactive material
comprises a plurality of granules of potassium perchlorate that
range in size from 40 to 400 mesh; e) 0 to 55% potassium chlorate
by mass, wherein the reactive material comprises a plurality of
granules of potassium chlorate that range in size from 40 to 400
mesh; g) 0 to 45% lithium perchlorate by mass wherein the reactive
material comprises a plurality of granules of lithium perchlorate
that range in size from 40 to 400 mesh; and h) 0 to 45% ceric
ammonium nitrate by mass, wherein the reactive material comprises a
plurality of granules of ceric ammonium nitrate that range in size
from 40 to 400 mesh.
6. The breaching round of claim 1, wherein the at least one fuel
includes at least one fuel selected from the group consisting of
guanidine nitrate, nitroguanidine, 5-amino tetrazole, and
nitrocellulose, and mixtures thereof.
7. The breaching round of claim 6, The projectile of claim 14,
wherein the reactive material is at least one of: a) 0 to 60%
guanidine nitrate by mass, wherein the reactive material comprises
a plurality of granules of guanidine nitrate that range in size
from 40 to 400 mesh; b) 0 to 60% nitroguanidine by mass, wherein
the reactive material comprises a plurality of granules of
nitroguanidine that range in size from 40 to 400 mesh; c) 0 to 60%
5-amino tetrazole by mass, wherein the reactive material comprises
a plurality of granules of 5-amino tetrazole that range in size
from 40 to 400 mesh; and d) 0 to 60% nitrocellulose by mass,
wherein the reactive material comprises a plurality of granules of
nitrocellulose that range in size from 40 to 400 mesh.
8. The breaching round of claim 1, wherein the reactive material
further comprises a dense inert metal powder.
9. The breaching round of claim 1, wherein the dense inert metal
powder comprises metal powder of at least one metal selected from
the group consisting of steel, stainless steel, tungsten, tantalum,
molybdenum, iron, and mixtures thereof, wherein the reactive
material is 0-75% the dense inert metal powder by mass, and the
metal powder comprises a plurality of granules of metal ranging in
size from 100 to 400 mesh.
10. A projectile comprising: a body comprising a base disposed at a
distal end of the body and a nose disposed at a proximal end of the
body, wherein the body is formed of a castable eutectic mixture,
the castable eutectic mixture configured to be melted and cast,
wherein the body is configured to break into a plurality of
fragments upon impact with a target, and a cavity disposed in the
body; and a reactive material disposed in the cavity, the reactive
material comprising at least one oxidizer and at least one
fuel.
11. The projectile of claim 10, wherein the reactive material is
formulated without a binder.
12. The projectile of claim 10, wherein the cavity is disposed in
at least one of the nose of the body or the base of the body.
13. The projectile of claim 10, wherein the at least one oxidizer
includes at least one oxidizer selected from the group consisting
of ammonium perchlorate, ammonium nitrate, potassium nitrate,
potassium perchlorate, potassium chlorate, lithium perchlorate,
ceric ammonium nitrate, and mixtures thereof.
14. The projectile of claim 13, wherein the reactive material is at
least one of: a) 0 to 55% ammonium perchlorate by mass, wherein the
reactive material comprises a plurality of granules of ammonium
perchlorate that range in size from 40 to 400 mesh; b) 0 to 55%
ammonium nitrate by mass, wherein the reactive material comprises a
plurality of granules of ammonium nitrate that range in size from
40 to 400 mesh; c) 0 to 45% potassium nitrate by mass, wherein the
reactive material comprises a plurality of granules of potassium
nitrate that range in size from 40 to 400 mesh; d) 0 to 50%
potassium perchlorate by mass, wherein the reactive material
comprises a plurality of granules of potassium perchlorate that
range in size from 40 to 400 mesh; e) 0 to 55% potassium chlorate
by mass, wherein the reactive material comprises a plurality of
granules of potassium chlorate that range in size from 40 to 400
mesh; g) 0 to 45% lithium perchlorate by mass wherein the reactive
material comprises a plurality of granules of lithium perchlorate
that range in size from 40 to 400 mesh; and h) 0 to 45% ceric
ammonium nitrate by mass, wherein the reactive material comprises a
plurality of granules of ceric ammonium nitrate that range in size
from 40 to 400 mesh.
15. The projectile of claim 10, wherein the at least one fuel
includes at least one fuel selected from the group consisting of
guanidine nitrate, nitroguanidine, 5-amino tetrazole, and
nitrocellulose, and mixtures thereof.
16. The projectile of claim 15, wherein the reactive material is at
least one of: a) 0 to 60% guanidine nitrate by mass, wherein the
reactive material comprises a plurality of granules of guanidine
nitrate that range in size from 40 to 400 mesh; b) 0 to 60%
nitroguanidine by mass, wherein the reactive material comprises a
plurality of granules of nitroguanidine that range in size from 40
to 400 mesh; c) 0 to 60% 5-amino tetrazole by mass, wherein the
reactive material comprises a plurality of granules of 5-amino
tetrazole that range in size from 40 to 400 mesh; and d) 0 to 60%
nitrocellulose by mass, wherein the reactive material comprises a
plurality of granules of nitrocellulose that range in size from 40
to 400 mesh.
17. The projectile of claim 10, wherein the reactive material
further comprises a dense inert metal powder.
18. The projectile of claim 17, wherein the dense inert metal
powder comprises metal powder of at least one metal selected from
the group consisting of steel, stainless steel, tungsten, tantalum,
molybdenum, iron, and mixtures thereof, wherein the reactive
material is 0-75% the dense inert metal powder by mass, and the
metal powder comprises a plurality of granules of metal ranging in
size from 100 to 400 mesh.
19.-20. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application may be related to U.S. patent application
Ser. No. ______, filed Apr. ______, 2020 by Swanson et al., and
entitled "Castable Frangible Projectile" (attorney docket no.
0913.02), the disclosure of which is incorporated herein by
reference, in its entirety, for all purposes.
COPYRIGHT STATEMENT
[0002] A portion of the disclosure of this patent document contains
material that is subject to copyright protection. The copyright
owner has no objection to the facsimile reproduction by anyone of
the patent document or the patent disclosure as it appears in the
Patent and Trademark Office patent file or records, but otherwise
reserves all copyright rights whatsoever.
FIELD
[0003] The present disclosure relates, in general, to breaching
rounds and more specifically to breaching round with a castable
frangible projectile and reactive material charge.
BACKGROUND
[0004] Conventional breaching rounds have been used by the military
and law enforcement to quickly gain entry into barricaded areas.
Traditionally, breaching ammunition has typically relied on
non-reactive projectiles made form copper, lead, steel, or tungsten
to physically destroy or otherwise overcome locking mechanisms and
other hardware of doors, gates, or other entryways. The shotgun
breaching round has been used for many years, relying on
traditional buckshot or slugs to defeat door hardware. Some
breaching rounds have utilized traditional frangible projectiles to
further limit collateral damage caused by overpenetration of
breaching rounds. However, conventional breaching rounds utilize
pressed or sintered powders of metals, metal oxides, and polymeric
materials. These conventional breaching rounds, however, are
limited to shotgun platforms, and are unable to be scaled to
smaller projectiles, or to be used in higher velocity,
rifled-barrel platforms.
[0005] Conventional reactive material projectiles have also been
used for breaching applications. However, conventional reactive
material projectiles typically incorporate use of a binder material
in the formulation of the reactive materials, as well as reactive
materials that produce high thermal energies that result in fire
and smoke that is undesirable.
[0006] Accordingly, an enhanced breaching round, and tools and
techniques for creating an enhanced breaching round are
provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] A further understanding of the nature and advantages of
particular embodiments may be realized by reference to the
remaining portions of the specification and the drawings, in which
like reference numerals are used to refer to similar components. In
some instances, a sub-label is associated with a reference numeral
to denote one of multiple similar components. When reference is
made to a reference numeral without specification to an existing
sub-label, it is intended to refer to all such multiple similar
components.
[0008] FIG. 1A is a schematic side perspective view of a castable
frangible projectile small arms cartridge, in accordance with
various embodiments.
[0009] FIG. 1B is a schematic longitudinal section of the small
arms cartridge, in accordance with various embodiments.
[0010] FIG. 2A is a schematic side perspective view of a castable
frangible projectile shotgun shell, in accordance with various
embodiments.
[0011] FIG. 2B is a schematic longitudinal section of the castable
frangible projectile shotgun shell, in accordance with various
embodiments.
[0012] FIG. 3A is a schematic side perspective view of a castable
frangible projectile 40 mm round, in accordance with various
embodiments.
[0013] FIG. 3B is a schematic longitudinal section of the castable
frangible projectile 40 mm round, in accordance with various
embodiments.
[0014] FIG. 4 is a flow diagram of a method of manufacturing a
castable frangible projectile, in accordance with various
embodiments.
[0015] FIG. 5 is a flow diagram of a method of manufacturing an
enhanced breaching round utilizing a castable frangible projectile,
in accordance with various embodiments.
DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS
[0016] While various aspects and features of certain embodiments
have been summarized above, the following detailed description
illustrates a few exemplary embodiments in further detail to enable
one of skill in the art to practice such embodiments. The described
examples are provided for illustrative purposes and are not
intended to limit the scope of the invention.
[0017] In the following description, for the purposes of
explanation, numerous specific details are set forth in order to
provide a thorough understanding of the described embodiments. It
will be apparent to one skilled in the art, however, that other
embodiments may be practiced without some of these specific
details. Several embodiments are described herein, and while
various features are ascribed to different embodiments, it should
be appreciated that the features described with respect to one
embodiment may be incorporated with other embodiments as well. By
the same token, however, no single feature or features of any
described embodiment should be considered essential to every
embodiment of the invention, as other embodiments of the invention
may omit such features.
[0018] Unless otherwise indicated, all numbers used herein to
express quantities, dimensions, and so forth used should be
understood as being modified in all instances by the term "about."
In this application, the use of the singular includes the plural
unless specifically stated otherwise, and use of the terms "and"
and "or" means "and/or" unless otherwise indicated. Moreover, the
use of the term "including, " as well as other forms, such as
"includes" and "included," should be considered non-exclusive.
Also, terms such as "element" or "component" encompass both
elements and components comprising one unit and elements and
components that comprise more than one unit, unless specifically
stated otherwise.
[0019] In an aspect, a breaching round is provided. The breaching
round includes a case defining a volume, a propellant disposed in
the volume of the case, and a projectile coupled to the case. The
projectile may comprise a base disposed at a distal end of the body
and a nose disposed at a proximal end of the body. The base of the
body may be disposed at least partially within the case and
configured to enclose the propellant within the volume of the case.
The body may be formed of a castable eutectic mixture, the castable
eutectic mixture configured to be melted and cast. The body may
further be configured to break into a plurality of fragments upon
impact with a target. A cavity may be provided between the distal
end and the proximal end of the body, and a reactive material may
be disposed in the cavity, the reactive material comprising at
least one oxidizer and at least one fuel.
[0020] In another aspect, a projectile is provided. The projectile
includes a body comprising a base disposed at a distal end of the
body and a nose disposed at a proximal end of the body, wherein the
body is formed of a castable eutectic mixture, the castable
eutectic mixture configured to be melted and cast, wherein the body
is configured to break into a plurality of fragments upon impact
with a target. A cavity may be disposed in the body, and a reactive
material disposed in the cavity, the reactive material comprising
at least one oxidizer and at least one fuel.
[0021] In a further aspect, a method of manufacturing an enhanced
breaching round is provided. The method includes casting a
projectile from a castable eutectic mixture in its melted form,
wherein the castable eutectic mixture comprises at least bismuth,
tin, and lead, wherein the mass percentage of bismuth is between
50-100%, tin is between 0-50%, and lead is 0-25%, and cooling the
projectile, wherein the projectile is configured to break into a
plurality of fragments upon impact with a target. The method may
further include providing, in the projectile, a cavity disposed
between a proximal end and a distal end of the projectile. The
method continues by forming a pellet of reactive material, wherein
forming the pellet of reactive material comprises pressing together
a blend of reactive material, the blend of reactive material
comprising at least one oxidizer and at least one fuel to form the
pellet, the at least one oxidizer comprising a plurality of
oxidizer granules ranging in size between 100-400 mesh, the at
least one fuel comprising a plurality of fuel granules, ranging in
size between 100-400 mesh, and filling the cavity of the projectile
with the pellet of reactive material, and sealing the cavity with
an adhesive compound.
[0022] Various modifications and additions can be made to the
embodiments discussed without departing from the scope of the
invention. For example, while the embodiments described above refer
to particular features, the scope of this invention also includes
embodiments having different combination of features and
embodiments that do not include all of the above described
features.
[0023] FIG. 1A is a schematic side perspective view of a castable
frangible projectile small arms cartridge 100A, in accordance with
various embodiments. The castable frangible projectile small arms
cartridge 100A includes a castable frangible projectile 105 having
a nose section 110, cavity 125, and base 130, casing 115, and
primer 120. It should be noted that the various components of the
castable frangible projectile small arms cartridge 100A (also
referred to herein as "cartridge system" for brevity) are
schematically illustrated in FIG. 1A, and that modifications to the
cartridge system 100A may be possible in accordance with various
embodiments.
[0024] In various embodiments, the castable frangible projectile
105 may include a nose 110 and base 130. The castable frangible
projectile 105 may further include a nose cavity 125 located at the
nose 110. The castable frangible projectile 105 may be coupled to
the casing 115. In some embodiments, the castable frangible
projectile 105 may be coupled to the casing 115 via a press-fit,
crimping, or other method of mechanical coupling as known to those
skilled in the art. As illustrated in FIG. 1A, the castable
frangible projectile 105 may be positioned within the casing 115,
such that at least part of the castable frangible projectile 105,
including the base 130, is positioned inside the casing 115, the
casing 115 creating a seal circumferentially around the body of the
castable frangible projectile 105. Casing 115 may further include a
primer 120 located at the base of the casing 115.
[0025] In various embodiments, the cartridge system 100A may be an
elongated structure, having a proximal end 135 and distal end 140
defining a longitudinal axis z-z. Each of the casing 115 and
castable frangible projectile 105 may further comprise a respective
proximal end 135 and respective distal end 140 defining a
respective longitudinal axis z-z of each of the casing 115 and
castable frangible projectile 105. Thus, the body of the casing 115
and the body of the castable frangible projectile 105 may
respectively be elongated in shape, and arranged collinearly along
the longitudinal axis z-z.
[0026] In some embodiments, the casing 115 may be a brass casing
that is cylindrical in shape, comprising an opening located at the
proximal end 135, and base located at the distal end 140. The
opening of the casing 115 may be configured to receive at least
part of the castable frangible projectile 105, such that the distal
end 140 of the castable frangible projectile 105 may be pressed
into the opening of the casing 115 starting with the base 130 of
the castable frangible projectile 105. Accordingly, in some
embodiments, an inner diameter of the opening of the casing may be
greater than an outer diameter of the base 130 of the castable
frangible projectile 105. The casing 115 may further be configured
to contain a propellant within a cavity defined between the base of
the casing 115 and the base 130 of the castable frangible
projectile 105. The propellant may include, without limitation,
nitrocellulose, nitroglycerine, nitroguanidine, or other suitable
gunpowder accelerant formulations, as known to those skilled in the
art. The casing 115 may further include a primer 120 located at the
base of the casing 115, and configured to initiate combustion of
the propellant held within the casing 115. Accordingly, primer 120
may include, without limitation, impact-sensitive (e.g., a
percussion primer) or other shock-sensitive, or
electrically-activated primers, as known to those skilled in the
art. Accordingly, in some embodiments, the base of the casing 115
may further include a rim, or alternatively, the base of the casing
115 may be rimless, as dependent on the respective form factor
needed for a given firearm platform.
[0027] In various embodiments, the castable frangible projectile
105 may have an elongated body, cylindrical in shape at the base
130 at a distal end 140. The cylindrical shape may continue to some
point between the base 130 and the nose 110. In some examples, the
point may be a mid-point along the longitudinal axis z-z of the
castable frangible projectile 105, centered between the base 130
and the nose 110. In some embodiments, the point may be located
before the mid-point, closer to the distal end 140, or after the
mid-point, closer to the proximal end 135. In various embodiments,
the diameter of the castable frangible projectile 105 may taper in
size from the point located between the base 130 and the nose 110
towards the nose 110. Thus, the body of the castable frangible
projectile 105 may decrease in diameter, moving from the point
towards the nose 110. Accordingly, in some embodiments, the nose
110 may be smaller in diameter than the base 130. The nose 110 may
have a generally parabolic cross-sectional shape, while in other
embodiments, the nose 110 may taper to a pointed tip, as in a
spitzer bullet, as known to those skilled in the art. In some
further embodiments, the nose 110 may include a cavity 125. The
cavity 125 may be configured to cause fragmentation of at least the
nose 110 of the castable frangible projectile 105, and to encourage
further fragmentation of the body of the castable frangible
projectile 105. In some embodiments, the cavity 125 may be
configured such that stress from an impact is concentrated over a
smaller surface area. In some embodiments, the cavity 125 may be
created during casting of the castable frangible projectile 105,
for example by utilizing a mold in which a cavity 125 is present in
the nose 110. Alternatively, the cavity 125 of the castable
frangible projectile 105 may be created in post-machining (e.g.,
after the casting process), for example, by drilling the cavity
into the nose 110 of the castable frangible projectile 105. In some
further embodiments, the cavity 125 may be filled, while in other
embodiments, the cavity 125 may remain unfilled. For example, in
some embodiments, the cavity 125 may be filled with a ballast
material, which may be a granular powder-like material. Suitable
ballast material may include, without limitation, steel, iron,
carbon, titanium, zirconium, tantalum, molybdenum, tungsten,
nickel, zinc, or aluminum. In further embodiments, the cavity 125
may be filled with a reactive material, as will be described in
greater detail below, with respect to FIG. 5.
[0028] Similarly, in some embodiments, the base 130 or other part
of the body of the castable frangible projectile 105, may further
comprise a cavity (not shown), which may similarly be configured to
encourage fragmentation of the castable frangible projectile 105
upon impact with a target. In some embodiments, the cavity may be
an internal cavity inside the body of the castable frangible
projectile 105. In other embodiments, the cavity may be created
going into the body from an external surface of the body.
Furthermore, like the cavity 125, the cavity at the base 130 or
other part of the body of the castable frangible projectile 105 may
further be filled with a ballast material, as described above, or
with a reactive material, as will be described in greater detail
below, with respect to FIG. 5. Thus, in some embodiments, the
cartridge system 100A may be a breaching round comprising a
castable frangible projectile encapsulating a reactive material
charge
[0029] FIG. 1B is a schematic longitudinal section of the small
arms cartridge 100B, in accordance with various embodiments.
Accordingly, FIG. 1B schematically depicts internal components of
the cartridge system 100B. The cartridge system 100B includes the
castable frangible projectile 105 and the casing 115. A volume 160
may be defined between the base 130 of the castable frangible
projectile 105 and the casing 115, which may be filled with a
propellant as described above. The castable frangible projectile
105 may include a nose cavity 125 filled with filler material 145,
an internal cavity 150a, a base cavity 150b, stress concentrator
150c, and one or more grooves 155. It should be noted that the
various components of the cartridge system 100B are schematically
illustrated in FIG. 1B, and that modifications to the cartridge
system 100B may be possible in accordance with various
embodiments.
[0030] In various embodiments, the castable frangible projectile
105 may be a one or more standard sizes for small arms projectiles.
For example, in some embodiments, the size of the castable
frangible projectile 105 may be scaled to various standard sizes,
including, without limitation, handgun, rifle, and other small arms
calibers and sizes. For example, the size of the castable frangible
projectile may include, without limitation, .22 caliber, 5.7 mm
(.224 caliber), 7.62 mm (.308 caliber), 9 mm, .357 caliber, .40
caliber, .44 caliber, .45 caliber, and .50 caliber. Similarly, the
cartridge system 100A may include cartridges with projectiles of
the corresponding size, such as, without limitation, .22 long
rifle, 9.times.19 mm Parabellum, 5.56.times.45 mm NATO, .300 AAC
blackout, .40 S&W, .45 ACP, among other cartridges as known to
those skilled in the art. The castable frangible projectile may
further be scaled to various sizes of shotgun ammunition,
including, without limitation, 12-gauge, 20 gauge, 28 gauge, and
.410 bore projectiles, as will be described with respect to FIGS.
2A & 2B. The castable frangible projectile 105 may further be
scaled to the size of a 40 mm projectile, as described in greater
detail with respect to FIGS. 3A & 3B. Thus, the castable
frangible projectile 105 may be scaled to any size of projectile
for a given application or platform.
[0031] In various embodiments, the castable frangible projectile
105 may be produced from a eutectic mixture, which may be a blend
of metals, ceramics, composites, and other material powders. For
example, in some embodiments, the composition of the castable
frangible projectile 105 may be selected based on the
manufacturability, ballistic performance, and frangibility of the
projectile. In some embodiments, the eutectic mixture may comprise
bismuth, tin, and lead, in its granular form that has been heated
above its melting point such that all component materials are
melted, well mixed, and cast into a desired projectile shape. In
some embodiments, the eutectic mixture may comprise 50 to 100
percent bismuth by mass percentage, 0 to 50 percent tin by mass
percentage, and 0 to 25 percent lead by mass percentage. In some
embodiments, eutectic mixture may be a lead-free formulation.
[0032] In some embodiments, the frangibility of the castable
frangible projectile 105 may be modified as discussed in further
detail with respect to FIG. 4. In one example, the addition of one
or more additives (e.g., high density, high melting materials)
during the melting process may be utilized to alter the
frangibility characteristics of the castable frangible projectile
105. For example, the one or more additives may include metals,
ceramics, composite, and other materials added during the melt to
encourage frangibility of the castable frangible projectile 105.
The one or more additives may include, without limitation, steel,
iron, carbon, titanium, zirconium, tantalum, molybdenum, tungsten,
nickel, zinc, copper, aluminum, titanium oxide, molybdenum
trioxide, molybdenum sulfide, tungsten trioxide, iron oxide, copper
oxide, alumina, and silica.
[0033] In some embodiments, the castable frangible projectile 105
may be cast to further exhibit a ductility to survive engraving of
rifling into the castable frangible projectile 105. For example, in
some embodiments, the castable frangible projectile 105 may be
fired out of a rifled bore. Thus, the rifling in the bore may cause
rifling striations or grooves to be engraved into the body of
castable frangible projectile 105 as it travels down the rifled
bore at high pressures and/or high velocities. Accordingly, the
castable frangible projectile 105 is configured to be ductile
enough to survive engraving caused by a rifled bore, while
maintaining its ability to fragment upon impact with a target.
Thus, in various embodiments, a mass percentage of tin and/or lead
may be increased to increase the ductility of the castable
frangible projectile 105, while balancing the frangibility of the
castable frangible projectile 105 which decreases with higher
percentage mass of tin and/or lead.
[0034] In further embodiments, the castable frangible projectile
105 may include one or more grooves 155 engraved into the body of
the castable frangible projectile 105 in post-machining after the
castable frangible projectile 105 has been cast and cooled. For
example, in some embodiments, one or more grooves 155 may be
created in the body of the castable frangible projectile 105 to
facilitate coupling with the casing 115. For example, the one or
more grooves 155 may facilitate seating of the castable frangible
projectile 105 to a proper depth inside the casing 115, and further
to facilitate proper crimping of the casing 115 against the
castable frangible projectile 105. In some embodiments, the one or
more grooves 155 may be configured to facilitate formation of a
seal by the casing 115 around the castable frangible projectile
105. In yet further embodiments, the one or more grooves 155 may
include one or more rifling grooves for firing of the castable
frangible projectile 105 through, for example, a smoothbore. Thus,
the one or more rifling grooves may be configured to encourage
rotation of the castable frangible projectile as it travels down a
smoothbore. The one or more grooves 155 may, in some examples,
include one or more concentric grooves, one or more longitudinal
grooves, one or more helical grooves, or other projectile rifling
pattern as known to those skilled in the art.
[0035] In various embodiments, the castable frangible projectile
105 may further include one or more stress concentrators, such as
the nose cavity 125, one or more internal cavity 150a, base cavity
150b, and stress concentrator 150c. In various embodiments, the one
or more stress concentrators may create higher density and/or lower
density regions in the body of the castable frangible projectile
105. For example, in some embodiments, one or more of the nose
cavity 125, one or more internal cavity 150a, base cavity 150b, and
stress concentrators 150c may be filled with a granular ballast
material. In some embodiments, the granular ballast material may be
a higher density material than the eutectic mixture utilized to
create the body of the castable frangible projectile 105. In other
embodiments, the granular ballast material may be a lower density
material than the eutectic mixture utilized to create the body of
the castable frangible projectile 105. In further embodiments, the
one or more stress concentrators may be empty cavities. As
previously described, the ballast materials may include, without
limitation, a granular powder-like material. Suitable ballast
material may include, without limitation, steel, iron, carbon,
titanium, zirconium, tantalum, molybdenum, tungsten, nickel, zinc,
or aluminum. In further embodiments, one or more stress
concentrators, such as the nose cavity 125 or internal cavity 150a,
may be filled with a reactive material, as will be described in
greater detail below, with respect to FIG. 5. In some embodiments,
the one or more stress concentrators may be sealed with a sealing
material. Sealing materials may include, without limitation, a
polymeric material filling and/or coating, epoxy filling and/or
coating, wax, or other suitable polymeric material or adhesive.
[0036] Stress concentrators 150c, in addition to cavities such as
nose cavity 125, internal cavity 150a, or base cavity 150b, may
further include material that has been removed from the body so as
to direct stresses towards specific parts or in specific direction
within the body of the castable frangible projectile 105. Stress
concentrators, such as stress concentrator 150c, may create
specific weak points within the body of the castable frangible
projectile 105 at desired locations, such as locations that are
relatively more resistant to fragmentation compared to other parts
of the castable frangible projectile 105. For example, a nose 110
with nose cavity 125 may be more frangible than a base of the
castable frangible projectile. Thus, by removing material via the
creation of stress concentrators 150c, the stress concentrator 150c
may encourage fragmentation of the distal end 140 of the castable
frangible projectile 105. The stress concentrators 150c may further
be configured to encourage fragmentation along specific features of
the castable frangible projectile 105, for example by encouraging
initial fragmentation into two or more fragments upon impact with a
target prior to further fragmentation of each of the two or more
fragments following the initial fragmentation. Thus, in some
embodiments, the stress concentrators 150c may define weak points,
contours, or lines, similar to fault lines, along which the body of
the castable frangible projectile 105 may initially fragment to
form two or more discrete fragments. The two or more discrete
fragments may, subsequently, fragment further into a plurality of
smaller granules.
[0037] FIG. 2A is a schematic side perspective view of a castable
frangible projectile shotgun shell 200A, in accordance with various
embodiments. The castable frangible projectile shotgun shell 200A
includes a castable frangible projectile 205 having a nose section
210, nose cavity 225, and base 230, case 270, brass head 215, and
primer 220. It should be noted that the various components of the
castable frangible projectile shotgun shell 200A (also referred to
herein as a "cartridge system") are schematically illustrated in
FIG. 2A, and that modifications to the cartridge system 200A may be
possible in accordance with various embodiments.
[0038] In various embodiments, the castable frangible projectile
205 may include a nose 210 and base 230. The castable frangible
projectile 205 may further include a nose cavity 225 located at the
nose 210. The castable frangible projectile 205 may be disposed
inside the case 270 and/or brass head 215. In some embodiments, the
castable frangible projectile 205 may be contained within the case
270, or alternatively, coupled to the brass head 215 via a
press-fit, crimping, or other method of mechanical coupling as
known to those skilled in the art. As illustrated in FIG. 2A, the
castable frangible projectile 205 may be fully encased within the
case 270, the case 270 sealing the entirety of the castable
frangible projectile 205. Brass head 215 may further include a
primer 220 located at the rim of the brass head 215.
[0039] In various embodiments, as previously described with respect
to FIG. 1A, the cartridge system 200A may be an elongated
structure, having a proximal end 235 and distal end 240 defining a
longitudinal axis z-z. Each of the case 270, brass head 215, and
castable frangible projectile 205 may further comprise a respective
proximal end 235 and respective distal end 240 defining a
respective longitudinal axis z-z. Each of the body of the case 270,
brass head 215, and the body of the castable frangible projectile
205 may respectively be elongated in shape, and arranged
collinearly along the longitudinal axis z-z.
[0040] In various embodiments, the case 270 may be a substantially
cylindrical structure. Similarly, the brass head 215 also be
cylindrical in shape. In some embodiments, the brass head 215 may
further include a rim at its base. The brass head 215 may include
an opening located at a proximal end 235, configured to receive the
case 270 and a powder charge. The case 270 may comprise an inner
volume and an opening at its distal end 240. The case 270 may be
configured to be inserted, from a distal end, into the opening of
the brass head 215. The case 270 may be configured to contain, in
its inner volume, the castable frangible projectile 205, wadding
260 (not shown), and at least part of the powder charge.
Accordingly, the brass head 215 and/or the case 270 may further be
configured to contain the powder charge within a cavity defined
between the base of the brass head 215 and the base of the wadding
in the case 270. The powder charge may include propellant may
include, without limitation, nitrocellulose, nitroglycerine,
nitroguanidine, or other suitable gunpowder accelerant
formulations, as known to those skilled in the art. The brass head
215 may further include a primer 220 located at the base of the
brass head 215, and configured to initiate combustion of the
propellant held within the brass head 215. Accordingly, primer 220
may include, without limitation, impact-sensitive (e.g., a
percussion primer) or other shock-sensitive, or
electrically-activated primers, as known to those skilled in the
art.
[0041] In some embodiments, castable frangible projectile 205 may
be a 12-gauge projectile. In other embodiments, the castable
frangible projectile 205 may be other sizes of projectile,
including, without limitation, a 20 gauge, 28 gauge, or .410 bore
projectile. Thus, the castable frangible projectile 205 may have an
elongated body, cylindrical in shape at the base 230 at a distal
end 240. The cylindrical shape may continue to some point between
the base 230 and the nose 210. In some examples, the point may be a
mid-point along the longitudinal axis z-z of the castable frangible
projectile 205, centered between the base 230 and the nose 210. In
some embodiments, the point may be located before the mid-point,
closer to the distal end 240, or after the mid-point, closer to the
proximal end 235. As previously described, in various embodiments,
the diameter of the castable frangible projectile 205 may taper in
size, starting from the point located between the base 230 and the
nose 210, and moving towards the nose 210. Thus, the body of the
castable frangible projectile 205 may decrease in diameter, moving
from the point towards the nose 210.
[0042] As with the castable frangible projectile of the cartridge
system 100A, the nose 210 of the castable frangible projectile 205
may have a generally parabolic cross-sectional shape, while in
other embodiments, the nose 210 may taper to a pointed tip, as in a
sabot projectile or spitzer bullet. In some further embodiments,
the nose 210 may include a cavity 225. The cavity 225 may be
configured to cause fragmentation of at least the nose 210 of the
castable frangible projectile 205 upon impact with a target, and to
encourage further fragmentation of the body of the castable
frangible projectile 205.
[0043] Accordingly, in various embodiments, the castable frangible
projectile 205 may be a monolithic slug in the castable frangible
projectile shell 200A. In other embodiments, the castable frangible
projectile shell 200A may include a plurality of shot pellets. Each
of the shot pellets may individually be a castable frangible
projectile 205 as described herein. Size of shot may include,
without limitation, any size of buckshot, waterfowl shot, birdshot,
clay shot, or pest shot, as known to those skilled in the art.
[0044] FIG. 2B is a schematic longitudinal section of the castable
frangible projectile shotgun shell 200B, in accordance with various
embodiments. Accordingly, FIG. 2B schematically depicts internal
components of the cartridge system 200B. The cartridge system 200B
includes the castable frangible projectile 205, wadding 260, case
270, and brass head 215. A volume 265 may be defined between the
base of the wadding 260 and the base of the brass head 215. The
volume 265 may be filled with a propellant as described above. The
castable frangible projectile 205 may include a nose cavity 225
filled with filler material 245, an internal cavity 250a, a base
cavity 250b, stress concentrator 250c, and one or more grooves 255.
It should be noted that the various components of the cartridge
system 200B are schematically illustrated in FIG. 2B, and that
modifications to the cartridge system 200B may be possible in
accordance with various embodiments.
[0045] In various embodiments, the castable frangible projectile
205 may be scaled to various sizes of shotgun ammunition,
including, without limitation, 12-gauge, 20 gauge, 28 gauge, and
.410 bore projectiles, as described above. As previously described,
the castable frangible projectile 205 may be produced from a
eutectic mixture, which may be a blend of metals, ceramics,
composites, and other material powders. In some embodiments, the
eutectic mixture may comprise bismuth, tin, and lead, in its
granular form that has been heated above a melting point of the
eutectic mixture, such that all component materials are melted,
well mixed, and cast into a desired projectile shape. In some
embodiments, the melting point may be a first temperature that is
lower than a melting point of any of the component materials
individually. In some embodiments, the eutectic mixture may
comprise 50 to 100 percent bismuth by mass percentage, 0 to 50
percent tin by mass percentage, and 0 to 25 percent lead by mass
percentage. In some embodiments, eutectic mixture may be a
lead-free formulation.
[0046] As previously described, in some embodiments, the
frangibility of the castable frangible projectile 205 may be
modified with the addition of one or more additives (e.g., high
density, high melting materials) during the melting process to
further improve the frangibility characteristics of the castable
frangible projectile 205. For example, the one or more additives
may include metals, ceramics, composite, and other materials added
during the melt to encourage frangibility of the castable frangible
projectile 105. The one or more additives may include, without
limitation, steel, iron, carbon, titanium, zirconium, tantalum,
molybdenum, tungsten, nickel, zinc, copper, aluminum, titanium
oxide, molybdenum trioxide, molybdenum sulfide, tungsten trioxide,
iron oxide, copper oxide, alumina, and silica.
[0047] The castable frangible projectile 205 may also be cast to
further exhibit a ductility to survive engraving of rifling
grooves, such as one or more grooves 255, into the castable
frangible projectile 205. For example, most shotgun bores are
smoothbores. Thus, the castable frangible projectile 205 may have
one or more grooves 255 engraved into its body via post-machining,
or alternatively, the castable frangible projectile may be cast
utilizing a mold exhibiting the one or more grooves 255. The one or
more grooves 255 may, in some examples, include one or more
concentric grooves, one or more longitudinal grooves, one or more
angled grooves, one or more helical grooves, or other projectile
rifling pattern as known to those skilled in the art.
[0048] In various embodiments, the castable frangible projectile
205 may further include one or more stress concentrators, such as
the nose cavity 225, one or more internal cavity 250a, base cavity
250b, and stress concentrator 250c. In various embodiments, the one
or more stress concentrators may create higher density and/or lower
density regions in the body of the castable frangible projectile
205. For example, in some embodiments, one or more of the nose
cavity 225, one or more internal cavity 250a, base cavity 250b, and
stress concentrators 250c may be filled with a granular ballast
material. In some embodiments, the granular ballast material may be
a higher density material than the eutectic mixture utilized to
create the body of the castable frangible projectile 205. In other
embodiments, the granular ballast material may be a lower density
material than the eutectic mixture utilized to create the body of
the castable frangible projectile 205. In further embodiments, the
one or more stress concentrators may be empty cavities. As
previously described, the ballast materials may include, without
limitation, a granular powder-like material. Suitable ballast
material may include, without limitation, steel, iron, carbon,
titanium, zirconium, tantalum, molybdenum, tungsten, nickel, zinc,
or aluminum. In further embodiments, one or more stress
concentrators, such as the nose cavity 225 or internal cavity 250a,
may be filled with a reactive material, as will be described in
greater detail below, with respect to FIG. 5. Thus, in some
embodiments, the cartridge system 200A, 200B may be a breaching
round comprising a castable frangible projectile encapsulating a
reactive material charge. In some embodiments, the one or more
stress concentrators may be sealed with a sealing material. Sealing
materials may include, without limitation, a polymeric material
filling and/or coating, epoxy filling and/or coating, wax, or other
suitable polymeric material or adhesive.
[0049] Stress concentrators 250c, in addition to cavities such as
nose cavity 225, internal cavity 250a, or base cavity 250b, may
further include material that has been removed from the body so as
to direct impact stresses towards specific parts or in specific
direction within the body of the castable frangible projectile 205.
Stress concentrators, such as stress concentrator 250c, may create
weak points within the body of the castable frangible projectile
205 at desired locations, such as locations that are relatively
more resistant to fragmentation compared to other parts of the
castable frangible projectile 205. The stress concentrators 250c
may further be configured to encourage initial fragmentation of the
castable frangible projectile 205 into two or more fragments upon
impact with a target prior to further fragmentation of each of the
two or more fragments following the initial fragmentation. Thus, in
some embodiments, the stress concentrators 250c may define weak
points, contours, or lines, similar to fault lines, along which the
body of the castable frangible projectile 205 may initially
fragment to form two or more discrete fragments. The two or more
discrete fragments may, subsequently, fragment further into a
plurality of smaller granules.
[0050] In various embodiments, the cartridge system 200B may
include a plurality of shot pellets, each of shot pellet of the
plurality of shot pellets a respective castable frangible
projectile 205. In such embodiments, each respective castable
frangible projectile 205 may be spherical in shape, like a ball.
The plurality of shot pellets may be disposed in a cup of the wad
260. The wad 260 may, accordingly, include a cup structurally
incorporated into the wad disposed at the proximal end of the wad
260. The cup may be configured to hold the plurality of shot
pellets within the case 270.
[0051] FIG. 3A is a schematic side perspective view of a castable
frangible projectile 40 mm round 300A, in accordance with various
embodiments. The castable frangible projectile 40 mm round 300A
includes a castable frangible projectile 305 having a nose section
310, nose cavity 325, and base 330, casing 315, rotating band 360,
and primer 320. It should be noted that the various components of
the castable frangible projectile 40 mm round 300A (also referred
to herein as a "cartridge system") are schematically illustrated in
FIG. 3A, and that modifications to the cartridge system 300A may be
possible in accordance with various embodiments.
[0052] In various embodiments, the castable frangible projectile
305 may include a nose 310 and base 330. The castable frangible
projectile 305 may further include a nose cavity 325 located at the
nose 310. The castable frangible projectile 205 may be disposed
inside the casing 315. In some embodiments, the castable frangible
projectile 305 may be coupled to the casing. In various
embodiments, the casing 315 may be crimped, press-fit, or otherwise
mechanically coupled to the castable frangible projectile 305. In
some further embodiments, the rotating band 360 may be configured
to be coupled to the casing 315, and further to coupled the
castable frangible projectile 305 to the casing 315. As illustrated
in FIG. 3A, the castable frangible projectile 305 may be at least
partially disposed within the casing 315. Casing 315 may further
include a primer 320 located at a base of the casing 315.
[0053] In various embodiments, as previously described with respect
to FIGS. 1A & 2A, the cartridge system 300A may be an elongated
structure, having a proximal end 335 and distal end 340 defining a
longitudinal axis z-z. The casing 315 and castable frangible
projectile 305 may further comprise a respective proximal end 335
and respective distal end 340 defining a respective longitudinal
axis z-z. The casing 315 and the body of the castable frangible
projectile 205 may respectively be elongated in shape, and arranged
collinearly along the longitudinal axis z-z.
[0054] In various embodiments, the casing 315 may be a
substantially cylindrical structure. The casing 315 may include an
opening located at a proximal end 335, configured to receive the
base 330 of the castable frangible round 305. The casing 315 may be
configured to contain, in an inner volume, at least part of the
distal end 340 of the castable frangible projectile 305 including
the base 330, and a propellant charge. Accordingly, the casing 315
may further be configured to contain the propellant charge within a
volume defined between the base of the casing 315 and the base 330
of the castable frangible projectile 305. The propellant charge may
include, without limitation, nitrocellulose, nitroglycerine,
nitroguanidine, or other suitable gunpowder accelerant
formulations, as known to those skilled in the art. The casing 315
may further comprise a primer 320, located at the base of the
casing 315, which is configured to initiate combustion of the
propellant charge in the casing 315. Accordingly, primer 320 may
include, without limitation, impact-sensitive (e.g., a percussion
primer) or other shock-sensitive, or electrically-activated
primers, as known to those skilled in the art.
[0055] In some embodiments, castable frangible projectile 305 may
be a 40 mm projectile (e.g., 40 mm in diameter). Thus, the castable
frangible projectile 305 may have an elongated body, cylindrical in
shape at the base 330 at a distal end 340. Like the castable
frangible projectile 105 in FIG. 1A, the cylindrical shape may
continue to some point between the base 330 and the nose 310. In
some examples, the point may be a mid-point along the longitudinal
axis z-z of the castable frangible projectile 305, centered between
the base 330 and the nose 310. In some embodiments, the point may
be located before the mid-point, closer to the distal end 340, or
after the mid-point, closer to the proximal end 335. As previously
described, in various embodiments, the diameter of the castable
frangible projectile 305 may taper in size, starting from the point
located between the base 330 and the nose 310, and moving towards
the nose 310. Thus, the body of the castable frangible projectile
305 may decrease in diameter, moving from the point towards the
nose 310.
[0056] As with the castable frangible projectile 105 of the
cartridge system 100A, the nose 310 of the castable frangible
projectile 305 may have a generally parabolic cross-sectional
shape, while in other embodiments, the nose 310 may taper to a
pointed tip, as in a sabot projectile or spitzer bullet. In some
further embodiments, the nose 310 may include a cavity 325. The
cavity 325 may be configured to cause fragmentation of at least the
nose 310 of the castable frangible projectile 305 upon impact with
a target, and to encourage further fragmentation of the body of the
castable frangible projectile 305.
[0057] In various embodiments, the rotating band 360 may be
configured to engage the rifling of a 40 mm projectile launcher
tube, and thus cause rotation of the castable frangible projectile
305. The rotating band 360 may thus be a feature formed from the
body of the castable frangible projectile 305, or may be a distinct
structure that is coupled to the castable frangible projectile
305.
[0058] FIG. 3B is a schematic longitudinal section of the castable
frangible projectile 40 mm round 300B, in accordance with various
embodiments. Accordingly, FIG. 3B schematically depicts internal
components of the cartridge system 300B. The cartridge system 300B
includes the castable frangible projectile 305, rotating band 360,
and casing 315. The cartridge system 300B may further comprise a
volume 365 defined between the base 330 of the castable frangible
projectile 305 and the base of the casing 315. The volume 365 may
be filled with a propellant as described above. The castable
frangible projectile 305 may include a nose cavity 325 filled with
filler material 345, an internal cavity 350a, a base cavity 350b,
stress concentrator 350c, and rotating band 360. It should be noted
that the various components of the cartridge system 300B are
schematically illustrated in FIG. 3B, and that modifications to the
cartridge system 300B may be possible in accordance with various
embodiments.
[0059] As previously described, the castable frangible projectile
305 may be produced from a eutectic mixture, which may be a blend
of metals, ceramics, composites, and other material powders. In
some embodiments, the eutectic mixture may comprise bismuth, tin,
and lead, in its granular form that has been heated above a melting
point of the eutectic mixture, such that all component materials
are melted, well mixed, and cast into a desired projectile shape.
Like with the castable frangible projectiles 105, 205, the melting
point of the eutectic mixture may be a first temperature that is
lower than a melting point of any of the component materials
individually. In some embodiments, the eutectic mixture may
comprise 50 to 100 percent bismuth by mass percentage, 0 to 50
percent tin by mass percentage, and 0 to 25 percent lead by mass
percentage. In some embodiments, eutectic mixture may be a
lead-free formulation.
[0060] As previously described, in some embodiments, the
frangibility of the castable frangible projectile 305 may be
modified with the addition of one or more additives (e.g., high
density, high melting materials) during the melting process to
further improve the frangibility characteristics of the castable
frangible projectile 305. For example, the one or more additives
may include metals, ceramics, composite, and other aluminum,
titanium oxide, molybdenum trioxide, molybdenum sulfide, tungsten
trioxide, iron oxide, copper oxide, alumina, and silica.
[0061] In some embodiments, the castable frangible projectile 305
may also be cast to include rotating band 360, or alternatively,
the rotating band may be created in post-machining. Alternatively,
the rotating band 360 may be coupled to the castable frangible
projectile 305 via mechanical coupling (e.g., press-fit) or thermal
coupling (e.g., welding).
[0062] In various embodiments, the castable frangible projectile
305 may further include one or more stress concentrators, such as
the nose cavity 325, one or more internal cavity 350a, base cavity
350b, and stress concentrator 350c. As previously described, in
some embodiments, one or more of the nose cavity 325, one or more
internal cavity 350a, base cavity 350b, and stress concentrators
350c may be filled with a granular ballast material. In some
embodiments, the granular ballast material may be a higher density
material than the eutectic mixture utilized to create the body of
the castable frangible projectile 305. In other embodiments, the
granular ballast material may be a lower density material than the
eutectic mixture utilized to create the body of the castable
frangible projectile 305. In further embodiments, the one or more
stress concentrators may be empty cavities. As previously
described, the ballast materials may include, without limitation, a
granular powder-like material. Suitable ballast material may
include, without limitation, steel, iron, carbon, titanium,
zirconium, tantalum, molybdenum, tungsten, nickel, zinc, or
aluminum. In further embodiments, one or more stress concentrators,
such as the nose cavity 325 or internal cavity 350a, may be filled
with a reactive material, as will be described in greater detail
below, with respect to FIG. 5. Thus, in some embodiments, the
cartridge system 300A, 300B may be a breaching round comprising a
castable frangible projectile encapsulating a reactive material
charge. In some embodiments, the one or more stress concentrators
may be sealed with a sealing material. Sealing materials may
include, without limitation, a polymeric material filling and/or
coating, epoxy filling and/or coating, wax, or other suitable
polymeric material or adhesive.
[0063] Stress concentrators 350c, in addition to cavities such as
nose cavity 325, internal cavity 350a, or base cavity 350b, may
further include material that has been removed from the body so as
to direct impact stresses towards specific parts or in specific
direction within the body of the castable frangible projectile 305.
Stress concentrators, such as stress concentrator 350c, may create
weak points within the body of the castable frangible projectile
305 to encourage fragmentation. The stress concentrators 250c may
further be configured to encourage fragmentation along specific
features of the castable frangible projectile 305, for example to
encourage an initial fragmentation into two or more fragments upon
impact with a target prior to further fragmentation of each of the
two or more fragments following the initial fragmentation. Thus, in
some embodiments, the stress concentrators 350c may define weak
points, contours, or lines, similar to fault lines, along which the
body of the castable frangible projectile 305 may initially
fragment to form two or more discrete fragments. The two or more
discrete fragments may, subsequently, fragment further into a
plurality of smaller granules.
[0064] FIG. 4 is a flow diagram of a method 400 of manufacturing a
castable frangible projectile, in accordance with various
embodiments. The method 400 begins, at block 405, by blending a
castable eutectic mixture. As described above, the castable
eutectic mixture comprises a blend of metallic powders. In some
embodiments, the castable eutectic mixture comprises a blend of
bismuth, tin, and lead, or any combination thereof. Thus, the
castable eutectic mixture may be a blended powder mixture of any
combination of powdered bismuth, tin, and/or lead.
[0065] Accordingly, in some embodiments, the eutectic mixture may
comprise 50 to 100 percent bismuth by mass (e.g., mass percentage),
0 to 50 percent tin by mass percentage, and 0 to 25 percent lead by
mass percentage, where mass percentage is a calculation of the
percentage by mass of a respective component (e.g., bismuth, tin,
or lead) of the mixture. Put another way, it is the ratio of the
mass of a respective component material to the total mass of the
mixture. The mass percentage of a component material may be given
by dividing the mass of the respective component material by the
total mass of the mixture, multiplied by 100 to give a
percentage.
[0066] In various embodiments, the composition of the eutectic
mixture may be changed, based on the desired characteristics for
the castable frangible projectile to be produced. For example, to
increase a ductility of the castable frangible projectile, the
eutectic mixture may comprise a higher mass percentage of tin
and/or lead. In some embodiments, the castable eutectic mixture may
comprise a lead-free blend of bismuth and tin. In some embodiments,
a mass percentage of bismuth may be increased to increase the
brittleness (and in turn the frangibility) of the castable
frangible projectile.
[0067] The method 400 may continue, at block 410, by heating the
castable eutectic mixture to a melting point of the eutectic
mixture. The melting point may be a first temperature at which the
eutectic mixture may melt into a liquid state. The first the
castable eutectic mixture may be heated to or above the first
temperature, which may be lower than a respective melting point of
any component material individually. For example, the eutectic
mixture of bismuth, tin, and/or lead may have a melting point at a
first temperature. The melting point of bismuth may be a second
temperature, higher than the first temperature. Similarly, the
melting point of tin may be a third temperature, higher than the
first temperature, and the melting point of lead may be a fourth
temperature higher than the first temperature. For example, the
eutectic mixture of bismuth, tin, and lead may have a melting point
at a first temperature, which may be between 94-98 degrees Celsius,
further depending on ambient pressure, and other environmental
factors as known to those skilled in the art. The respective
melting points of bismuth (Bi) (271.4 degrees Celsius), lead (Pb)
(327.5 degrees Celsius), and tin (Sn) (231.9 degrees Celsius), are
accordingly higher than that of the eutectic mixture. The eutectic
mixture may, thus, be heated to a first temperature at or above the
melting point of the eutectic mixture, creating a uniformly melted
eutectic mixture. The eutectic mixture, in its molten form, may
further be mixed to ensure a uniform blend of the component
materials. In some embodiments, the eutectic mixture may be
configured to maintain densities similar to conventional lead and
copper projectiles. In some examples, the castable frangible
projectile may be within +/-0-50% of the density of conventional
lead and copper projectiles.
[0068] The method 400 continues, at block 415, by introducing one
or more additives to the eutectic mixture during the melting
process. For example, once the eutectic mixture has been heated to
the first temperature, the one or more additives may be mixed into
the molten eutectic mixture. The one or more additives may include
high density and/or high melting point materials. In some
embodiments, the one or more additives may include metallic,
ceramic, and/or composite materials introduced during the melt to
encourage frangibility. The one or more additives may include,
without limitation, steel, iron, carbon, titanium, zirconium,
tantalum, molybdenum, tungsten, nickel, zinc, copper, aluminum,
titanium oxide, molybdenum trioxide, molybdenum sulfide, tungsten
trioxide, iron oxide, copper oxide, alumina, and silica. In some
embodiments, the one or more additives can range in size from 10 to
400 mesh.
[0069] Once the eutectic mixture has been heated above its melting
point and is well mixed, at block 420, the method 400 may continue
by casting a projectile from the melted eutectic mixture. For
example, in various embodiments, the molten eutectic mixture may be
cast into projectile molds. The projectile molds may include molds
for projectiles of various sizes and with various features. As
previously described, eutectic mixture may be cast into projectiles
for various small arms, for example, by casting into molds
configured to produce projectiles of various sizes, including, .22
caliber, 5.7 mm (.224 caliber), 7.62 mm (.308 caliber), 9 mm, .357
caliber, .40 caliber, .44 caliber, .45 caliber, and .50 caliber.
The molds may further be configured to produce various sizes of
shotgun projectiles, including, without limitation, 12-gauge, 20
gauge, 28 gauge, and .410 bore projectiles, including buckshot,
waterfowl shot, birdshot, slugs, and sabot rounds. In further
embodiments, the eutectic mixture may be cast into 40 mm
projectiles, for example by casting into molds configured to
produce 40 mm projectiles. Thus, the castable frangible projectile
may be scaled to any size of projectile for a given application or
platform.
[0070] At block 425, the method 400 may continue by creating one or
more stress concentrators in the projectiles. The one or more
stress concentrators may include one or more cavities in the nose,
base, internally, and one or more stress concentrators. In various
embodiments, the cavities in the projectiles may be created during
the casting process. For example, the mold may be configured to
include one or more cavities in the nose, base, or internally. The
mold may further include features of the one or more stress
concentrators, as described above. Alternatively, in some
embodiments, the cavities and/or stress concentrators may be
created in post-machining after the castable frangible projectile
has been cooled, at step 435 described below. Post-machining may
include drilling, engraving, or otherwise removing material from
the castable frangible projectile after it has been cooled, to
create the one or more cavities or stress concentrators.
[0071] Thus, the castable frangible projectile may be cast with a
cavity and/or one or more stress concentrators, or the cavities
and/or stress concentrators may be post-machined into the castable
frangible projectile. In various embodiments, the one or more
cavities may be created to have dimensions according to a desired
specification. For example, the one or more cavities may be created
to have a certain volume, specific depth, width, or length, to
create a desired opening or other features.
[0072] In various embodiments, the one or more cavities may be
empty, or alternatively filled with a ballast material, as previous
described. Ballast material may include, without limitation, steel,
iron, carbon, titanium, zirconium, tantalum, molybdenum, tungsten,
nickel, zinc, or aluminum. Ballast material may be granular in
form, ranging in size from 10 to 400 mesh. In some embodiments,
ballast material may be configured to increase penetration of the
castable frangible projectile. In further embodiments, the ballast
material may be configured to also increase the frangibility of the
castable frangible projectile.
[0073] Once filled with ballast material, the cavity may, in some
embodiments, be filled and/or sealed with a polymeric material or
adhesive, such as, without limitation, epoxy, wax, or other
polymeric material. Filling and sealing of the cavities may,
accordingly, be performed after casting and cooling of the castable
frangible projectile, as described at block 435.
[0074] At block 430, the method 400 may further include creating
rifling grooves in the castable frangible projectile. As with the
one or more stress concentrators, rifling grooves may be created in
the casting process or created in post-machining. In some
embodiments, rifling grooves may include grooves created in the
castable frangible projectile to encourage rotation (e.g., rifling)
of the projectile as it travels through a bore/the air. Rifling
grooves may include, without limitation, concentric grooves,
slanted grooves, longitudinal grooves, helical grooves, or other
rifling pattern as known to those skilled in the art.
[0075] In other embodiments, rifling grooves may be engraved into
the body of the castable frangible projectile when it is fired out
of a rifled bore as the castable frangible projectile travels down
the rifled bore at high velocity and pressure. Thus, to ensure that
the castable frangible projectile remains intact during the
creation of rifling grooves, whether through post-machining or
through engraving during firing of the castable frangible
projectile, the castable frangible projectile may be configured to
exhibit enough ductility to survive rifling without breaking apart
in the barrel, or during post-machining. In further embodiments,
the rifling grooves may include a feature of the frangible castable
projectile configured to engage the rifling of a bore, such as, for
example, a rotating band of a 40 mm projectile.
[0076] At block 435, once the castable frangible projectiles have
been cast into respective molds, the hot castable frangible
projectiles may be cooled. In some embodiments, the castable
frangible projectiles may be quenched while still hot. Quenching
may be performed in water, oil, or cooled air to achieve or
otherwise maintain a desired crystalline structure, which may
further encourage frangibility of the castable frangible
projectile. In other embodiments, the castable frangible projectile
may not be quenched, and instead allowed to cool in ambient
temperature air. Thus, through the process of casting and cooling,
a crystalline structure may be created in the body of the castable
frangible projectile.
[0077] FIG. 5 is a flow diagram of a method 500 of manufacturing an
enhanced breaching round utilizing a castable frangible projectile,
in accordance with various embodiments. The method 500 begins, at
block 505, by casting of the castable frangible projectile, as
described above with respect to FIG. 4. As previously described,
the castable frangible projectile may be cast from a eutectic
mixture that has been melted by heating to a first temperature that
is at or above the melting point of the eutectic mixture, but lower
than a melting point of any respective component material of the
eutectic mixture individually. The castable frangible projectile
may be cast according to various standard sizes of projectile,
including, without limitation, 22 caliber, 5.7 mm (.224 caliber),
7.62 mm (.308 caliber), 9 mm, .357 caliber, .40 caliber, .44
caliber, .45 caliber, and .50 caliber. The molds may further be
configured to produce various sizes of shotgun projectiles,
including, without limitation, 12-gauge, 20 gauge, 28 gauge, and
.410 bore projectiles, including buckshot, waterfowl shot,
birdshot, slugs, and sabot rounds. In further embodiments, the
eutectic mixture may be cast into 40 mm projectiles, for example by
casting into molds configured to produce 40 mm projectiles. Thus,
the castable frangible projectile may be scaled to any size of
projectile for a given application or platform.
[0078] In various embodiments, the eutectic material may be
configured to maintain a similar density to conventional lead
and/or copper projectiles. For example, in some embodiments, the
castable frangible projectile may be configured to have a density
that is within +/-50% of the density of conventional lead and/or
copper ammunition.
[0079] Once the castable frangible projectile has been cast, the
method 500 may continue, at block 510, with cooling of the castable
frangible projectile. As previously described with respect to FIG.
4, cooling may include quenching of the castable frangible
projectile while it is still hot. Quenching may be performed in
water, oil, or cooled air to achieve or otherwise maintain a
desired crystalline structure, which may further encourage
frangibility of the castable frangible projectile. In other
embodiments, the castable frangible projectile may not be quenched,
and instead allowed to cool in ambient temperature air.
[0080] At block 515, the method 500 continues by providing one or
more cavities in the castable frangible projectile. As described
with respect to FIG. 4 above, the one or more cavities may be
created in the castable frangible projectile during casting (e.g.,
by using a mold configured to create the one or more cavities), or
by post-machining of the cavities (e.g., drilling, engraving,
etc.).
[0081] The one or more cavities may include cavities in the nose,
base, or an internal cavity. In various embodiments, the one or
more cavities may be created to have dimensions according to a
desired specification. For example, the one or more cavities may be
created to have a certain volume, specific depth, width, or length,
to create a desired opening or other features.
[0082] In various embodiments, some of the one or more cavities may
be empty, or alternatively filled with a ballast material, as
previous described. Ballast material may include, without
limitation, steel, iron, carbon, titanium, zirconium, tantalum,
molybdenum, tungsten, nickel, zinc, or aluminum. Ballast material
may be granular in form, ranging in size from 10 to 400 mesh. In
some embodiments, ballast material may be configured to increase
penetration of the castable frangible projectile. In further
embodiments, the ballast material may be configured to also
increase the frangibility of the castable frangible projectile.
[0083] Once filled with ballast material, the cavity may, in some
embodiments, be filled and/or sealed with a polymeric material or
adhesive, such as, without limitation, epoxy, wax, or other
polymeric material. Filling and sealing of the cavities may,
accordingly, be performed after casting and cooling of the castable
frangible projectile, as described at block 535.
[0084] The method 500 continues, at block 520, by creating a blend
of reactive material. In various embodiments, the reactive material
may comprise at least one oxidizer, at least one fuel, and no
binder. In various embodiments, the reactive material may be
configured to be a low-smoke formulation. For example, the reactive
material may be configured to use a fuel having a low flame
temperature.
[0085] In various embodiments, the at least one oxidizer may
include at least one of ammonium perchlorate, ammonium nitrate,
potassium nitrate, potassium perchlorate, potassium chlorate,
lithium perchlorate, or ceric ammonium nitrate. The at least one
fuel may include at least one of guanidine nitrate, nitroguanadine,
5-amino tetrazole, or nitrocellulose.
[0086] In various embodiments, the at least one oxidizer and the at
least one fuel may be powdered in form. Particle sizes for the at
least one oxidizer and the at least one fuel may range from 40 mesh
to 400 mesh. For example, in some embodiments, particles may vary
in size within the range of 40-400 mesh, or fall within a subrange
of sizes within the range of 40-400 mesh. In other embodiments, the
particles may be the same size, but fall within the range of 40-400
mesh, or may comprise a set of one or more particle sizes within
the range of 40-400 mesh.
[0087] In various embodiments, the mass percentages of the at least
one oxidizer and at least one fuel may vary depending on the type
of oxidizer and type of fuel used. For example, in some
embodiments, for the at least one oxidizer, the reactive material
may be 0 to 55% ammonium perchlorate by mass (e.g., mass
percentage), 0 to 55% ammonium nitrate by mass percentage, 0 to 45%
potassium nitrate by mass percentage, 0 to 50% potassium
perchlorate by mass percentage, 0 to 55% potassium chlorate by mass
percentage, 0 to 45% lithium perchlorate by mass percentage, and 0
to 45% ceric ammonium nitrate by mass percentage.
[0088] The reactive material may, in further embodiments, for the
at least one fuel, comprise 0 to 60% guanidine nitrate by mass
(e.g., mass percentage), 0 to 60% nitroguanidine by mass
percentage, 0 to 60% 5-amino tetrazole by mass percentage, and 0 to
60% nitrocellulose by mass percentage.
[0089] Accordingly, in various embodiments, the blend of reactive
material may be created by blending, in powdered form, the mixture
of the at least one oxidizer and at least one fuel in the mass
percentages described above. In various embodiments, mixing may
include physically stirring, sifting, milling, folding, or
otherwise incorporating the powders of the at least one oxidizer
with the powders of the at least one fuel.
[0090] In yet further embodiments, the reactive material may
include at least one dense inert metal (DIM), as known to those
skilled in the art, which may be blended with the at least one
oxidizer and the at least one fuel. DIMs may include, without
limitation, one or more types of metals, including at least one of
steel, stainless steel, tungsten, tantalum, molybdenum, or iron.
Like the at least one oxidizer and the at least one fuel, the DIM
may be a powder (e.g., DIM powder). In various embodiments, DIM
powder of different sizes may be utilized. Sizes may range from 100
mesh to 400 mesh granules. In various embodiments, the mass
percentages of DIM powder in the reactive material may be 0 to 75%.
In various embodiments, the DIM powder may be blended with the at
least one oxidizer and at least one fuel via physical mixing,
stirring, sifting, milling, folding, or otherwise incorporating the
DIM powder with the at least one oxidizer and at least one
fuel.
[0091] At block 525, the method 500 may continue by forming a
pellet of reactive material. In various embodiments, once the
reactive material has been blended, a pellet may be formed by
pressing the blend of reactive material powders into a pellet. At
block 530, the one or more cavities may be filled with the reactive
material pellet. For example, the reactive material pellet may be
inserted into one or more of the one or more cavities (e.g., nose,
base, and/or internal). At block 535, the reactive material may be
sealed in the cavity. Thus, in various embodiments, the pellet of
reactive material may be encased in the castable frangible
projectile, which may act as a frangible shell for delivering the
reactive material pellet. As previously described with respect to
the ballast materials, once the reactive material pellet has been
placed in the one or more cavities, the one or more cavities may be
sealed via a polymeric material or adhesive, such as, without
limitation, epoxy, wax, or other polymeric material. In yet further
embodiments, the reactive material may be sealed in a ceramic,
metal, or composite material.
[0092] Accordingly, the castable frangible breaching round may
include many advantages over traditional breaching ammunition. For
example, traditional breaching rounds rely on the size and mass of
a frangible projectile, which are typically fired out of smooth
bore barrels, such as a shotgun. Thus, weapons with rifled bores or
utilizing smaller caliber projectiles could not effectively be used
to breach entryways. Conventional breaching rounds, which rely on
the size and mass of a projectile to physically destroy a locking
mechanism of a door, gate, or other entryway are unable to be
scaled to different calibers and were limited in terms of effective
weapon platforms.
[0093] By providing a castable frangible projectile with a reactive
material charge (e.g., reactive material pellet) housed in one or
more cavities, a smaller caliber projectile may be used to
effectively breach a door, disrupting or destroying locking
mechanisms of a door, gate, or other entryway through the explosive
reaction caused upon impact of the reactive material charge with
the target. Moreover, by utilizing a castable frangible projectile
as described above, the castable frangible projectiles are further
able to be fired out of various weapons platforms that utilize
various sizes of projectile, rifled and smooth bore platforms, and
with the ability to survive even aggressive rifling encountered by
projectiles fired out of rifle cartridges.
[0094] While certain features and aspects have been described with
respect to exemplary embodiments, one skilled in the art will
recognize that numerous modifications are possible. For example,
the methods and processes described herein may be implemented using
various hardware, tools, and control components. Further, while
various methods and processes described herein may be described
with respect to certain structural and/or functional components for
ease of description, methods provided by various embodiments are
not limited to any single structural and/or functional architecture
but instead can be implemented on any suitable hardware
configuration. Similarly, while certain functionality is ascribed
to certain system components, unless the context dictates
otherwise, this functionality can be distributed among various
other system components in accordance with the several
embodiments.
[0095] Moreover, while the procedures of the methods and processes
described herein are described sequentially for ease of
description, unless the context dictates otherwise, various
procedures may be reordered, added, and/or omitted in accordance
with various embodiments. Moreover, the procedures described with
respect to one method or process may be incorporated within other
described methods or processes; likewise, system components
described according to a specific structural arrangement and/or
with respect to one system may be organized in alternative
structural arrangements and/or incorporated within other described
systems. Hence, while various embodiments are described with--or
without--certain features for ease of description and to illustrate
exemplary aspects of those embodiments, the various components
and/or features described herein with respect to one embodiment can
be substituted, added and/or subtracted from among other described
embodiments, unless the context dictates otherwise. Consequently,
although several exemplary embodiments are described above, it will
be appreciated that the invention is intended to cover all
modifications and equivalents within the scope of the following
claims.
* * * * *