U.S. patent number 3,762,329 [Application Number 05/173,079] was granted by the patent office on 1973-10-02 for lethal expandible projectile.
This patent grant is currently assigned to MB Associates. Invention is credited to Robert C. Mawhinney.
United States Patent |
3,762,329 |
Mawhinney |
October 2, 1973 |
**Please see images for:
( Certificate of Correction ) ** |
LETHAL EXPANDIBLE PROJECTILE
Abstract
A high penetration, short range projectile comprised of a shot
filled, deformable, flexible bag which is initially folded or
rolled for insertion in a conventional cartridge case of a small
firearm or the like, and adapted to be launched therefrom. Upon
exit from the muzzle of the small arm, the bag radially expands
under the influence of centrifugal force provided by the rifling
grooves within the barrel to provide a spin stabilized trajectory
characterized by a substantial energy decay in a relatively short,
preselected down range distance.
Inventors: |
Mawhinney; Robert C. (Danville,
CA) |
Assignee: |
MB Associates (San Ramon,
CA)
|
Family
ID: |
22630449 |
Appl.
No.: |
05/173,079 |
Filed: |
August 19, 1971 |
Current U.S.
Class: |
102/448;
102/449 |
Current CPC
Class: |
F42B
12/34 (20130101) |
Current International
Class: |
F42B
12/34 (20060101); F42B 12/02 (20060101); F42b
007/02 () |
Field of
Search: |
;102/38,41,42C,95,91 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Stahl; Robert F.
Claims
What is claimed is:
1. In combination with a cartridge case of a small arm or the like;
the cartridge case having an open end and a slightly enlarged end
wall relative to the outer surface of the case closing an opposite
end, a primer located in the enlarged end wall, a propellant charge
located in the case proximate the primer; a projectile
comprising:
a deformable container and a preselected number of particles
located therein, said container including at least one circularly
shaped member formed on a diameter which is substantially larger
than the diameter of the cartridge case, said member at least
partially defining an outer peripheral surface of said container
and being rolled on a diameter approximating the inside diameter of
the cartridge case whereby to accommodate insertion of said
projectile within said case.
2. The combination, as recited in claim 1, further comprising:
a gas check located in the cartridge case between the propellant
charge and said projectile; and
cap means for closing the open end of the cartridge case after
insertion of said projectile.
3. The combination, as recited in claim 1, wherein said particles
are grains of shot, and wherein the range of said projectile is a
function of the number of grains of shot.
4. The combination, as recited in claim 1, wherein said container
is a two-sided bag, said bag being fabricated from a first side of
canvas and a second side from a heat sensitive material, said first
side being bonded to said second side.
5. The combination, as recited in claim 2, wherein said cap means
is press fitted into the open end of the cartridge case, and
wherein said cap means is fabricated from a light weight plastic
material.
6. A cartridge for a small hand gun or the like including a case
having a primer and charge located in one end and a projectile
located in an opposite end, said projectile comprising:
an outer wall formed from a disc shaped deformable material, said
wall being rolled to define a cross-section in substantial
conformance to the cross-section of said case;
a plurality of particles located along and adjacent to a common
diameter of said wall; and
means for enclosing said particles relative to a surface of said
wall.
7. The cartridge, as recited in claim 6, wherein said wall includes
a marginal edge in overlapped relationship relative to an oppoiste
marginal edge thereof.
8. The cartridge, as recited in claim 6, wherein said means
includes an inner wall of identical shape to said outer wall and
wherein said inner and outer walls are connected together along
outer circumferential edges.
9. A cartridge for a small hand gun or the like including a case
having a primer and charge supported therein and a projectile
slidably located in an opposite end, said projectile
comprising:
particle means for providing preselected mass to said projectile;
and
deformable means for providing an enclosure for said particle
means, said deformable means including first and second circularly
shaped wall members each having an outside diameter greater than
the diameter of said case, with said diameter defining the
longitudinal length of said projectile, each of said wall members
including oppositely spaced lateral sides which are folded over the
define a cross-section of said projectile substantially equal to
the cross-section of said case, and with said particle means being
located along a common diameter of said wall members.
10. The cartridge, as recited in claim 9, wherein said common
diameter is parallel to the longitudinal axis of said case.
11. The cartridge, as recited in claim 9, wherein said wall members
are bonded together along an outer peripheral edge thereof.
12. A cartridge including a cylindrically shaped case and a
projectile located therein, said projectile comprising:
an outer wall formed from a flexible material and rolled about the
inner peripheral surface of said case;
an inner wall connected to said outer wall and rolled about the
inner peripheral surface of said outer wall; and
a plurality of particles located between said inner and outer
walls.
13. The cartridge, as recited in claim 12, wherein each of said
outer and inner walls are disc shaped and wherein each includes
oppositely spaced overlapped marginal edges.
14. The cartridge, as recited in claim 13, wherein said particles
are radially spaced on opposite sides in said case relative to said
overlapped edges and eccentrically located relative to the
longitudinal axis of said case.
15. The cartridge, as recited in claim 13, wherein the
cross-sectional perimeter of said outer wall and the diameter
thereof are equal.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates generally to the munitions art, and more
particularly to a high penetration, short range projectile adapted
to be fired by a small arm, such as a .38 caliber hand gun or the
like.
The beneficial effect of the use of firearms in a military
engagement, is substantially greater than a domestic law
enforcement encounter, due to the difference in environment wherein
the weapons are used. In military combat, when a member of the
armed forces directs a shot at a target, i.e. an enemy solider,
there is a good chance that the primary target may be in close
proximity to a number of secondary targets, such as additional
enemy soldiers. Should the fired projectile miss the primary
target, the possibility exists that a secondary target may be hit.
Even in the event of a complete miss, a certain degree of
suppression to the enemy forces is attained, and generally
speaking, except for the wasteful expenditures of ammunition, every
round directed against the enemy provides the firer with some
beneficial effect.
The environment in which firearms are used by domestic law
enforcement officials on the other hand is vastly different. This
difference results from the fact that the target is typically
surrounded, or in close proximity, to noncombatants (innocent
bystanders) as opposed to enemy soldiers. This situation can be
anticipated in all aspects of law enforcement, especially aircraft
hyjacking, bank robberies and fleeing felons. The domestic law
enforcement situation implies that the officer must hit his target
when he fires, or risk the catastrophic result of striking an
innocent bystander. Unlike military combat there are no benefits to
the officer if he was justified in firing, but misses his target.
Even the so-called "warning shot" fired in the air has a potential
range of over a mile and ultimately impacts with dangerously high
energy. Thus, it is inopportune and unfortunate that law
enforcement officers must rely on essentially the same ammunition
which was optimized for the military, such ammunition being
characterized by high lethality over an exceptionally long
range.
Ideally, optimum law enforcement ammunition should deliver a bullet
which would magically stop immediately after it passes by, or
through, the target i. e. a bullet on a string. While this solution
is not completely feasible in practice, it can be approached.
An unpowered projectile in horizontal flight has been found to be
retarded by aerodynamic forces. Neglecting gravity, it can be shown
that the velocity of an unpowered projectile, at any point down
range, is determined by the following equation:
V.sub.x = V.sub.o e .sup..sup.-x/.sup..lambda.
where
V.sub.x = velocity at some range x
V.sub.o = initial velocity
x = distance from muzzle
.lambda. = slowing down length = 2w/.rho.AC.sub.D
w = projectile weight
.rho. = air density
A = projectile presented area
C.sub.d = drag coefficient
If the muzzle velocity (V.sub.o) is assumed to be constant, the
only parameter which effects the down range velocity (V.sub.x) is a
slowing down length (.lambda.). It will be seen that if the slowing
down length is large, its velocity decay is very gradual.
Conversely, if the slowing down length (.lambda.) is small, then
the velocity degrades very rapidly. Examination of the factors
which determine the slowing down length (.lambda.) provides the
conclusion that only projectile weight (w), projectile presented
area (A), and drag coefficient (C.sub.D) can be manipulated to vary
the slowing down length (.lambda.).
Generally speaking, the projectile presented area (A) is fixed and
is nearly equal to the cross-sectional area of the bore of the
launcher, leaving only the projectile weight (w) and drag
coefficient (C.sub.D) of the projectile to be varied. The subject
projectile, however, allows the projectile area (A) to increase
after exit from the bore of the launcher which allows flexibility
in all three parameters. The above described technique is utilized
to drastically alter the ballistic properties of the subject
projectile in such a manner that the projectile may be made
relatively safe for any selected range.
With reference now to the subject invention, a novel type of
ammunition is disclosed, which can be optimized for law enforcement
work. The ammunition is adaptable to have conventional high
lethality, and effectiveness, at the muzzle and throughout the
typical encounter range, and rapidly become non-hazardous
thereafter. The inventive concept involves the use of a deformable
projectile in the form of a shot filled bag which, when folded and
packaged in a conventional cartridge case, requires no more volume
than a standard round. However, upon launch, as the projectile is
forced down the barrel, it engages the rifling grooves thereby
acquiring the spin rate necessary for acquiring stability. Upon
exit from the muzzle, the projectile is adapted to expand and
assume a disc-like shape due to the reactional centrifugal force
upon the slot particles within the bag. The enlarged disc-shape
provides an increased drag coefficeint (C.sub.D) and an increased
presented area (A) which afford substantial resistance to the
aerodynamic forces and predictable energy decay.
It is therefore a general object of the subject invention to
provide ammunition which is optimized for use in a law enforcement
situation.
It is another object of the subject invention to provide ammunition
useable in conjunction with conventional small arms, such as hand
guns or the like.
It is still another object of the present invention to provide a
deformable projectile which may be folded and packaged in a
conventional cartridge case.
It is yet another object of the subject invention to provide a
projectile having spin stabilized trajectory.
It is a further objective of the present invention to provide a
projectile which expands and assumes a disc-like shape under the
influence of centrifugal force.
It is still a further object of the present invention to provide a
projectile that is stable at the conventional muzzle velocities of
a small arm.
It is yet a further object of the subject invention to provide a
projectile having a substantial energy decay in a selected,
relatively short, down range distance.
It is still a further object of the subject invention to provide a
projectile characterized by high penetration on impact over a
relatively short range proximate the end of the launcher and by low
penetration on impact thereafter.
It is another object of the present invention to provide a
projectile which is easy to assemble, and economical to
manufacture.
Other advantages of the present invention will become apparent from
a consideration of the following detailed description taken in
conjunction with the accompanying drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an exemplary high penetration, short range
projectile of the subject invention, having an interior portion
broken away to disclose the interior content;
FIG. 2 is a perspective view of an assembled cartridge, with a
partial quarter section broken away, to disclose the interior
content thereof, including the projectile illustrated in FIG.
1;
FIG. 3 is a partial elevation of a small arm, with one half of the
barrel portion broken away, to illustrate the orientation of the
cartridge illustrated in FIG. 2;
FIG. 4 is the same partial elevation as in FIG. 3, illustrating the
separation of the projectile from the cartridge case immediately
after firing;
FIG. 5 is another partial elevation illustrating the relative
positions of the various components after exit from the barrel of
the exemplary small arm;
FIG. 6 is another partial elevation illustrating the fully expanded
projectile in trajectory towards its target.
FIG. 7 is an end view of the projectile illustrated in plan in FIG.
1;
FIG. 8 is a perspective view of the projectile illustrated in FIGS.
1 and 7 illustrating the location of the shot prior to the folding
step;
FIG. 9 is an end elevation of the projectile illustrated in FIG. 8,
taken in the direction of the numeral 9, showing a first edge
folded over the portion containing the shot;
FIG. 10 is the same end elevation as illustrated in FIG. 9 showing
a second edge folded over the first edge; and
FIG. 11 is a cross-sectional elevation of the small arm and
cartridge illustrated in FIG. 3 taken along the line 11--11
thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to FIGS. 1 and 7 of the drawings, and in
accordance with an exemplary embodiment of the subject invention, a
high penetration, short range projectile is indicated generally at
10. The projectile 10 is comprised of a two-sided, relatively thin,
disc-shaped bag 12 having a preselected number of grains of
suitably sized shot particles 14 disposed therein. One side of the
bag 12 is fabricated from a fabric, such as canvas, while the
second side preferably includes a heat sealable fabric which
provides an annular bond. Dimensionally for use with a .38 caliber
cartridge case and by way of example, the bag 12 measures
approximately one inch in diameter, but it will be appreciated that
the diameter could be altered to accommodate other sized cartridge
cases and also to affect the ballistic properties thereof. The size
and weight of the shot particles 14 may also be varied, but again
by way of example, No. 12 bird shot has been found to afford good
results with a .38 caliber weapon. As previously indicated, the
number of grains of shot 14 disposed within the bag 12 will depend
to some extent on the desired ballistics of the projectile 10 and
the design rangeability thereof in accordance with the slowing down
length (.lambda.).
To accommodate insertion into a small arms cartridge case or the
like, the flat configuration of the disc-shaped bag 12 must be
initially altered. As best observed in FIG. 8, the shot particles
14 are initially displaced from random locations thereon and urged
toward the center of the bag 12 by any suitable means such as by
squeezing the outer annular surfaces of the bag 12. The center
positioning of the shot particles 14 form a generally cylindrically
shaped diametrically extending, axially enlarged center portion
indicated generally at 11, which is generally oval shaped in cross
section as best observed in FIG. 9 and 10. The initial folding step
is illustrated in FIG. 9 wherein a first outer edge relative to the
center portion 11 is folded thereover. The final step is
illustrated in FIG. 10 wherein a diametrically opposite outer edge,
relative to the first outer edge, is folded or rolled over the
first edge to form an elongated generally cylindrical configuration
shaped similar to that of a "taco." In this ultimate configuration,
the bag 12 is of suitable cross section to be inserted in the open
end of a cartridge case.
With reference now to FIG. 2, a cylindrically shaped cartridge case
is indicated generally at 16, and may be any conventional cartridge
case adaptable for use with any type of small arm as for example a
.38 caliber hand gun or the like. One end of the case 16 is open,
as indicated at 18, with the opposite end being closed by an
annularly shaped, radially extending end wall portion 20 which
projects slightly outwardly from the cartridge case 16 for purposes
of being received in and seated in the receiver portion of a small
arm or the like as shall hereinafter be described. The end wall 20
further includes a primer portion 22 adapted to be struck by the
firing pin of a small arm as is conventional in the art. The
propellant for the projectile 10 is provided by a powder charge 24
disposed within the cartridge case 16 adjacent the end wall 20,
retained therein by means of a relatively thin cylindrically shaped
bulkhead or gas check 26. Interposed between the gas check 26 and a
relatively thin, cone shaped, end cap 28 is the suitably deformed
projectile 10. Preferably the end cap 28 and gas check 26 are
formed from a relatively light weight plastic so as to contribute
negligible weight to the assembled cartridge for purposes to be
subsequently explained. Additionally, it will be noted that the
projectile 10 in its nested position is easily packaged in the
conventional cartridge case 16, with the assembled case 16
requiring no more volume than a standard round.
FIGS. 3 and 11 of the drawings illustrate an exemplary small arm 30
which includes a barrel portion 31 having a front iron sight at 34
and internal rifling grooves designated by 36. The left end of the
barrel 30 is suitably counterbored as indicated at 32, to receive
the radially enlarged end wall 20 of the cartridge case 16. The
small arm 30 may be any hand operated or shoulder supported weapon,
and for purposes of illustration will be considered a .38 caliber
hand gun having internal rifling grooves 36. The cartridge 16 is
indicated in the pre-firing position disposed in the receiver
portion 32, the small arm 30 having a firing pin (not shown)
suitably located and adapted to strike the primer 22. Upon release
of the firing pin by any suitable means, such as pull of a trigger,
the firing pin will strike the primer 22 thereby detonating the
propellant or powder charge 24. Since the cartridge case 16 is
restrained by the engagement of the counterbore or receiver 32 and
the enlarged end wall 32, the detonation force of the propellant
launches the gas check 26, the projectile 10, and the end cap 28
towards the muzzle end of the barrel 30. By means of the internal
rifling grooves 36 within the barrel 30, it will be noted that
rotation is imparted to the projectile 10 as well as longitudinal
thrust.
FIG. 4 indicates the relation of the elements immediately after
detonation of the propellant charge 24, wherein the gas check 26,
projectile 10, and end cap 28 are disunited from the case 16 and
FIG. 5 indicates the relation of the components upon exit from the
barrel 30. The end cap 28 and gas check 26 have appreciably less
mass than the projectile 10 and therefore due to aerodynamic
forces, separate from the trajectory line of the projectile 10. Due
to rotation of the projectile 10 provided by the rifling grooves
36, the centrifugal force imposed on the shot particles 14 to
radially displace from the center portion 11 and cause the
projectile 10 to radially expand, the projectile 10 now assuming a
substantially disc shape of enlarged transverse cross section and
dimensionally relatively thin with respect to the axis of
trajectory.
FIG. 6 illustrates the projectile 10 in its fully radially expanded
shape proceeding in its trajectory in a manner calculated to
provide substantial energy decay in a relatively short preselected
down range distance, and further providing substantial impact
energy against a target between the muzzle of the small arm 30 and
the preselected distance.
It will be noted that the projectile 10 is adapted to have
predictable ballistic characteristics, such characteristics being
predictable by the design of the presented cross-sectional area,
the basic configuration of the projectile in flight, and the number
of grains of shot disposed in the bag 12 which provides the mass to
the projectile. Thus, the ballistic characteristics of the
projectile 10 are such that the impact energy may be effectively
dissipated in any desired distance. It will further be appreciated
that the subject invention provides a novel type of ammunition
which can be optimized for use in the law enforcement environment.
The projectile can have conventional high lethality and
effectiveness proximate the muzzle and throughout the typical
encounter range, and ultimately become rapidly non-hazardous
thereafter. It will be further noted that the projectile 10 will be
completely spin stabilized in flight due to the reaction of the
imposed centrifugal force acting upon the shot 14, the centrifugal
force and spin rate being initiated by the rifling grooves 36.
While it will be appreciated that the embodiments illustrated
herein are calculated to fulfill the objects above stated, it will
be appreciated that the subject invention is susceptible to
modification, variation and change without departing from the scope
of the invention.
* * * * *