U.S. patent application number 16/660327 was filed with the patent office on 2020-04-23 for method of achieving controlled, variable ballistic dispersion in automatic weapons.
The applicant listed for this patent is Harry Arnon. Invention is credited to Harry Arnon.
Application Number | 20200124388 16/660327 |
Document ID | / |
Family ID | 70280142 |
Filed Date | 2020-04-23 |
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United States Patent
Application |
20200124388 |
Kind Code |
A1 |
Arnon; Harry |
April 23, 2020 |
METHOD OF ACHIEVING CONTROLLED, VARIABLE BALLISTIC DISPERSION IN
AUTOMATIC WEAPONS
Abstract
A method of achieving controlled, variable ballistic dispersion
in an automatic weapon is disclosed includes providing a plurality
of cartridges, where each cartridge has a case and a projectile
partially inserted into a mouth of the case forming a
circumferential joint between the projectile and the mouth of the
cartridge and held therein at a different pull strength. The method
also includes providing a plurality of adhesive sealants, where
each adhesive sealant of the plurality of adhesive sealants sets a
design bullet pull strength that is different from each other
adhesive sealant.
Inventors: |
Arnon; Harry; (Sanford,
FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Arnon; Harry |
Sanford |
FL |
US |
|
|
Family ID: |
70280142 |
Appl. No.: |
16/660327 |
Filed: |
October 22, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62748853 |
Oct 22, 2018 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F42B 5/067 20130101;
F42B 33/001 20130101; F42B 5/285 20130101; F42B 30/02 20130101;
F41A 27/04 20130101; F42B 5/073 20130101 |
International
Class: |
F42B 33/00 20060101
F42B033/00; F42B 5/285 20060101 F42B005/285; F42B 30/02 20060101
F42B030/02 |
Claims
1. A method of achieving variable ballistic dispersion from an
automatic weapon, the method comprising: assembling a plurality of
ammunition cartridges such that each of the plurality of ammunition
cartridges has a different respective predetermined pull strength;
packaging the plurality of ammunition cartridges into a group for
firing sequentially from an automatic weapon.
2. The method of claim 1, wherein assembling the plurality of
ammunition cartridges includes applying a respective adhesive
sealant to each of the plurality of ammunition cartridges in a
respective circumferential joint between a respective case mouth
and a respective projectile thereof, the respective adhesive
sealants being formulated with different adhesive properties so as
to achieve the different respective predetermined pull
strengths.
3. The method of claim 2, wherein applying the respective adhesive
sealant to each of the plurality of ammunition cartridges includes
injecting the respective adhesive sealant into the respective
circumferential joint with an applicator having a non-contact jet
valve.
4. The method of claim 3, wherein each of the respective adhesive
sealants is formulated to wick around the respective
circumferential joint upon injection.
5. The method of claim 2, wherein applying the respective adhesive
sealant to each of the plurality of ammunition cartridges includes
passing each of the plurality of ammunition cartridges down a
common production line and applying each of the respective adhesive
sealants from a respective applicator.
6. The method of claim 5, wherein each of the respective
applicators uses a non-contact jet valve to inject the respective
adhesive sealant into the respective circumferential joint.
7. The method of claim 2, wherein assembling the plurality of
ammunition cartridges further includes at least partially curing
each of the respective adhesive sealants using ultraviolet (UV)
radiation.
8. The method of claim 1, wherein each of the different respective
predetermined pull strengths is at least 125 pounds force
(lbf).
9. The method of claim 8, wherein the different respective pull
strengths vary from 125 lbf to 300 lbf.
10. The method of claim 1, wherein the plurality of ammunition
cartridges include at least three ammunition cartridges having the
different respective predetermined pull strengths.
11. The method of claim 10, wherein the plurality of ammunition
cartridges include four ammunition cartridges having the different
respective predetermined pull strengths.
12. A method of achieving variable ballistic dispersion from an
automatic weapon, the method comprising: passing a plurality of
ammunition cartridges along a production line with at least first
and second portions of the plurality of ammunition cartridges
having respective adhesive sealants applied to respective
circumferential joints between respective case mouths and
respective projectiles thereof; wherein the respective adhesive
sealants are formulated with different adhesive properties such
that the first and second portions of the plurality of ammunition
cartridges will have different respective predetermined pull
strengths.
13. The method of claim 12, wherein each of the respective adhesive
sealants is applied from a different applicator.
14. The method of claim 12, wherein each of the respective adhesive
sealants is applied from at least one applicator having a
non-contact jet valve.
15. The method of claim 14, wherein each of the respective adhesive
sealants is formulated to wick around the respective
circumferential joints upon injection.
16. The method of claim 12, further comprising passing the
plurality of ammunition cartridges past at least one ultraviolet
(UV) light and at least partially curing each of the respective
adhesive sealants using UV radiation.
17. The method of claim 12, further comprising packaging the
plurality of ammunition cartridges into a group for firing
sequentially from an automatic weapon with ammunition cartridges
from the first and second portions being interspersed.
18. A group of ammunition cartridges arranged for firing
sequentially from an automatic weapon, the group comprising: a
first ammunition cartridge having a first predetermined pull
strength of a first circumferential joint between a first case
mouth and a first projectile; and a second ammunition cartridge
having a second predetermined pull strength of a second
circumferential joint between a second case mouth and a second
projectile, the first and second predetermined pull strengths being
different.
19. The group of claim 18, wherein the first and second
predetermined pull strengths are determined by first and second
adhesive sealants located, respectively, in first and second
circumferential joints.
20. The group of claim 18, further comprising a third ammunition
cartridge having a third predetermined pull strength of a third
circumferential joint between a third case mouth and a third
projectile, the third predetermined pull strength being different
from both the first and second predetermined pull strengths.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 62/748,853, filed on Oct. 22, 2018, the
contents of which are herein incorporated by reference in their
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to small arms ammunition, and
more particularly, to a method of achieving controlled, variable
ballistic dispersion in automatic weapons.
BACKGROUND OF THE INVENTION
[0003] In firearms, ballistic dispersion is the pattern of bullet
strikes on the target which diverge from the point of aim due to a
variety of factors. Some examples of factors that may cause
dispersion include a worn or defective firearm, variations in
ammunition components or velocity, and wind or atmospheric
conditions which result in a spread of impacts in the vertical and
horizontal orientations.
[0004] Historically, the goal of ammunition and firearm makers has
been to decrease dispersion for greater accuracy in firearms. The
primary mechanism available to ammunition makers to decrease
dispersion is by controlling the shot start velocity of the
bullets. When two otherwise identical bullets are fired from the
same weapon, at the same target with the same aim point, under the
same ambient conditions, but at different velocities, the slower
projectile will strike the target at a lower point than the faster
projectile. This is due to varying ballistic trajectories which
initially coincide at close range and diverge to a greater degree
as the distance to the target increases.
[0005] The two factors leading to a consistent shot start velocity
are a consistent propellant charge and a consistent pull strength
(the force required to remove the bullet from the case mouth). A
higher propellant charge will generally result in a higher shot
start velocity. Likewise, a higher pull strength will in a higher
shot start velocity, as a higher pressure is able to build within
the cartridge before the bullet is released from the case.
Generally, consistent pull strengths are achieved through
consistent case thicknesses, compositions, annealing levels and
crimp strength.
[0006] A consistent shot start velocity is particularly critical in
long range rifles, where the difference in ballistic trajectories
resulting from different velocities will have the most impact upon
the actual point of impact. Consequently, great pains are taken to
ensure as uniform a possible propellant charge and pull strength in
ammunition rounds used by snipers, competition shooters, and the
like.
[0007] With automatic firearms, accuracy is generally less
important as such weapons are often used produce a suppressive
field of fire over a larger area rather to place rounds on a
specific target. Users of these weapons are often trained to scan
the weapon side-to-side during fire to enhance this effect. While
the effectiveness of modern machine guns is unquestioned, further
improvements are possible.
SUMMARY OF THE INVENTION
[0008] A method of achieving controlled, variable ballistic
dispersion in an automatic weapon is disclosed. The method includes
providing a plurality of cartridges, where each cartridge has a
case and a projectile partially inserted into a mouth of the case
forming a circumferential joint between the projectile and the
mouth of the cartridge and held therein at a different pull
strength. The method also includes providing a plurality of
adhesive sealants, where each adhesive sealant of the plurality of
adhesive sealants sets a design bullet pull strength that is
different from each other adhesive sealant. The method also
includes applying a different adhesive sealant to the
circumferential joint of each of the plurality of cartridges,
exposing the plurality of cartridges to UV radiation or other
curing agent until the different adhesive sealants cure to develop
the design bullet pull strength, and combining the plurality of
cartridges having the different adhesive sealants in an ammunition
belt to form a plurality of different velocities and trajectories
of respective projectiles when fired in an automatic weapon.
[0009] In view of the foregoing, it is an object of the present
invention to provide a method of achieving controlled, variable
ballistic dispersion in automatic weapons. These and other objects,
aspects and advantages of the present invention will be better
appreciated in view of the drawings and following detailed
description of preferred embodiments.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1A is an exploded schematic view of a cartridge;
[0011] FIG. 1B is a schematic view of the cartridge of FIG. 1A with
a projectile inserted into a case thereof;
[0012] FIG. 2 is a schematic view of a back end of the case of FIG.
1A taken in the direction of line 2-2;
[0013] FIG. 3 is a schematic view of applicators applying adhesive
sealants in accordance with the invention;
[0014] FIG. 4 is a schematic view of a UV light curing the adhesive
sealants shown in FIG. 3; and
[0015] FIG. 5 is a schematic view illustrating a range of
dispersion of projectiles.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] In the summary of the invention, provided above, and in the
descriptions of certain preferred embodiments of the invention,
reference is made to particular features of the invention, for
example, method steps. It is to be understood that the disclosure
of the invention in this specification includes all possible
combinations of such particular features, regardless of whether a
combination is explicitly described. For instance, where a
particular feature is disclosed in the context of a particular
aspect or embodiment of the invention, that feature can also be
used, to the extent possible, in combination with and/or in the
context of other particular aspects and embodiments of the
invention, and in the invention generally.
[0017] Referring initially to FIGS. 1A-1B and 2, a conventional
cartridge 100 includes a projectile (i.e., a bullet) 102 held
partially within a case 104 forming a circumferential joint 110
between the projectile and the mouth of the case 104. The case 104
contains a propellant for ejecting the bullet 102 from the case 104
when the cartridge 100 is fired. The cartridge 100 also includes a
back end 106 (surrounded by a rim grippable by a firearm ejector
mechanism) opposite the bullet 102. The rim 106 typically houses a
primer cup 108 filled with primer which ignites when struck with a
firing pin, and which in turn ignites the propellant.
[0018] Referring additionally to FIG. 3, an adhesive sealant 112,
115, 117, 119 is being applied to a plurality of cartridges 100A,
1006 on a first production line 120. The adhesive sealant 112, 115,
117, 119 is selected in order to set the bullet pull strength by
bonding the projectile 102 to the case 104 in accordance with an
aspect of the invention. The adhesive sealant 112, 115, 117, 119 is
formulated to adhere to the case 104 and the projectile 102 with a
defined shear strength along the circumferential joint 110. Thus,
selecting a particular adhesive sealant 112, 115, 117, 119
determines the pull strength needed to separate the projectile 102
from the case 104.
[0019] In this example, a plurality of adhesive sealants are
provided 112, 115, 117, 119 where each adhesive sealant of the
plurality of adhesive sealants 112, 115, 117, 119 is formulated to
have adhesive properties that will result in a design bullet pull
strength that is different from that resulting from each other
adhesive sealant. In a particular aspect of the invention, each of
the adhesive sealants 112, 115, 117, 119 masks crimping variables,
reducing their consequences and homogenizing the final bullet pull
strength. The adhesive sealants 112, 115, 117, 119 accomplish this
masking effect through even distribution around the joint 110
formed between the cartridge case mouth and base of the projectile
102. This even distribution, due to the low viscosity and wicking
properties of the adhesive sealants 112, 115, 117, 119 results in
the desired bullet pull strength from each of the adhesive sealants
112, 115, 117, 119 and a stable release and flight pattern for the
bullets.
[0020] The plurality of adhesive sealants 112, 115, 117, 119 are
used in order to achieve varying desired design bullet pull
strengths in a group of cartridges. As illustrated in FIG. 3, the
plurality of adhesive sealants are applied using applicators 114,
118 that include non-contact precision jet valves 113, 116. The jet
valves 113, 116 apply the respective adhesive sealant 112, 115,
117, 119 to the cartridge case mouth 110 and bullet 102 at the
circumferential joint 110 of each of the cartridges 100A, 100B. The
plurality of adhesive sealants 112, 115, 117, 119 are specially
formulated to exhibit very low viscosity and to wick around the
cartridge case mouth along circumferential joint 110 resulting in a
smooth, consistent distribution of the adhesive sealant 112, 115,
117, 119.
[0021] Accordingly, more than one variation of adhesive sealant can
be applied from different dispensers 114, 118 or sealant reservoirs
112A, 115A, 117A, 119A, which alternate in the passing of completed
cartridges to achieve different bullet pull strengths. By
substituting this method of sealing for the existing process, the
ability to environmentally seal and either increase or decrease
bullet pull strength (i.e. neck tension) in any number of
variations greater than one may be achieved on the same production
line 120.
[0022] Referring now to FIG. 4, the adhesive sealant 112, 115, 117,
119 is then cured in place on cartridges 100A, 100B, 100C, 100D on
a second production line 130 using a UV light 122 having an array
of UV LED curing lights 123A, 123B, 123C, 123D, 123E. At the
desired wavelength and intensity, the UV exposure needed is no more
than a few seconds. Further subsurface curing occurs anaerobically.
The particular adhesive sealant 112, 115, 117, 119 is exposed to UV
radiation until the particular adhesive sealant cures to develop
the design bullet pull strength. After UV radiation curing is
completed, the cartridges 100A, 100B, 100C, 100D, can be handled,
tested, packaged and shipped in minutes without ever leaving the
assembly line. The present invention is not necessarily limited to
UV curing. For instance, adhesives cured via visible light could be
used.
[0023] In a particular aspect of the invention, the adhesive
sealant 112, 115, 117, 119 may have a composition comprising
polyglycol dimethacrylate of 30-60% by weight, polyglycol
dioctanoate of 30-60% by weight, saccharin of 1-5% by weight,
cumene hydroperoxide of 1-5% by weight, and a photoinitiator of
1-5% by weight.
[0024] The adhesive sealant 112, 115, 117, 119 contains no class 1
ozone depleting chemicals. Accordingly, an additional advantage of
the adhesive sealant 112, 115, 117, 119 described herein is that it
is 100% active with no solvents. This eliminates the toxic fumes
and allows the adhesive sealant 112, 115, 117, 119 to be applied
continuously creating efficiency gains over previous batch
processing methods.
[0025] The adhesive sealant 112, 115, 117, 119 may maximize bullet
pull strength at approximately 300 lbf. As bullet pull strength
increases, so does the pressure inside the case 104 prior to the
bullet 102 firing. Accordingly, the adhesive sealants 112, 115,
117, 119 may be formulated to achieve a desired range of bullet
pull strengths. For example, the bullet pull strength range may be
from 125 lbf to 300 lbf. It will be appreciated that the total pull
strength is also a result of the bonded surface area in the
circumferential joint. This is impacted by caliber and other
dimensional factors.
[0026] Referring additionally to FIG. 5, increasing or decreasing
bullet pull strength has been shown to increase or decrease
velocity of the projectile significantly without propellant loading
variations. FIG. 5 illustrates the relationship between velocity
and varying impact on the target. The same angle of firing with
bullets launched at different velocities results in higher or lower
impacts on the target. For example, a shooter 200 is aiming an
automatic weapon 202 at the same angle while firing rounds with
each having a different adhesive sealant with different bullet pull
strength. As a result the cone of dispersion 204 of the bullets
strike the ground at varying distances along different trajectories
206, 208, 210 and 212. Thus, the round having the highest bullet
pull strength due to the adhesive sealant will have the highest
velocity and the farthest trajectory 206. The round having the
least bullet pull strength due to the adhesive sealant will have
the lowest velocity and the least trajectory 212, and so forth.
[0027] In one aspect, application of an adhesive sealant with a
higher bullet pull strength to a cartridge resulted in a gain of
130 feet per second over an unsealed cartridge and 102 feet per
second gain over a lower strength sealant which itself exceeded the
unsealed cartridge by 28 feet per second. With a base velocity of
2,575 for the unsealed cartridge, the low strength adhesive sealant
velocity would be 2,603 and the high strength velocity at 2,705
feet per second.
[0028] According to ballistic tables for the .30 caliber 147 grain
Full Metal Jacketed NATO projectile, applying low strength yields
-12.86 Minute of Angle (MOA) of drop at 500 yards while higher
strength results in -11.74 MOA of drop, which is a difference of
1.12 MOA or a 5.6'' difference through the adhesive sealant
alone.
[0029] In a particular aspect, the cartridges 100A, 100B, are
presented along a belt 120 which separates and aligns them. Instead
of a single dispenser applying the same adhesive sealant, multiple
dispensers 114, 118 apply different adhesive sealants 112, 115,
117, 119 from respective reservoirs 112A, 115A, 117A, 119A as
determined by a computerized control system.
[0030] For example, since four rounds of non-tracing ammunition are
later combined with a single tracing round in a pattern described
as "4+1" and the tracing ammunition would typically be sealed
separately in its own run, for example with a further differing
strength, every group of four non-tracing cartridges would receive
low 112, low to medium 115, medium to high 117 or high strength 119
adhesive sealant. When combined in the machine gun ammunition
linking machine, each of the rounds would then have a different
bullet pull strength and therefore a different point of bullet
release pressure and velocity as described above, despite being
otherwise identical (within manufacturing tolerances) with respect
to caliber, construction and propellant load.
[0031] The ability of the present invention to achieve variable
dispersion extends beyond the effect of different short start
velocities on trajectory. For example, in practical use of a
firearm including rounds with intentionally varied bullet
strengths, there will be increased dispersion effects to recoil
effects and cyclic rate variation.
[0032] In the case of the former, recoil in general causes the
muzzle of the automatic weapon to rise against the vehicle mount or
the shoulder of a ground user, so the lower the recoil impulse the
closer the next round is generally to the point of aim. Recoil
begins on the bolt face as soon as the primer is impacted. When
also considering the response of the weapon to different recoil
impulses, it will be appreciated that the higher shot start
pressures will add more significantly to the height of the impacts
while the lower pressure impacts should be close to the point of
aim or lower. For example, a weapon firing for one second at high
recoil levels would spread ten rounds wider in impact area on the
target than the same weapon firing a lower recoil round. Without as
much muzzle rise, the lower pressure ammunition would be expected
to have lower dispersion in automatic fire. The present invention,
by including a mix of both, can further achieve controlled
dispersion by taking into these recoil effects.
[0033] In the case of the latter, it is believed that the "dwell
time" between rounds is affected by increases or decreases in shot
start pressures in gas and recoil operated weapons. The use of
adhesive sealant, as described herein, to control the shot start
pressure is will consequently further increase dispersion due to
variable response of the weapon to the prior round's gas pressure
level. For example, a weapon loaded with all low strength sealants
would be expected to operate at a lower cyclic rate than those
loaded with high strength sealant due to higher pressures generated
internally from more complete propellant burn. A mixed belt of
ammunition would then be expected to operate at a variable cyclic
rate from round to round, amplifying the effect of shot pressures
alone on ballistic dispersion.
[0034] In general, the foregoing description is provided for
exemplary and illustrative purposes; the present invention is not
necessarily limited thereto. Rather, those skilled in the art will
appreciate that additional modifications, as well as adaptations
for particular circumstances, will fall within the scope of the
invention as herein shown and described and of the claims appended
hereto.
* * * * *