WO1981001046A1

WO1981001046A1 - Small arms ammunition

Info

Publication number: WO1981001046A1
Application number: PCT/US1980/001306
Authority: WO
Inventors: A Flatau
Original assignee: A Flatau
Priority date: 1979-10-05
Filing date: 1980-10-03
Publication date: 1981-04-16
Also published as: IT8025135A0; IT1133171B; GB2072309A; FR2466742A1; DE3049943A1; BE885607A; EP0039362A1

Abstract

Improved small arms projectile and small arms ammunition round containing such a projectile. Characteristically, the projectile is a hollow core projectile that takes the form of a tubular main body (20) with a tapered nose section (19) and a central core (17). In a low muzzle velocity mode of projectile, the hollow core (17) may be a cylinder. In a high muzzle velocity projectile, the nose portion (34) of the core is tapered, the outlet portion (41) is tapered and the ratio of the cross-section area of the throat (38) inside the main body of the projectile to the nose inlet (40) cross-section area is at least 0.5 to 1. The terminus (32) of the projectile is boat-tailed. The ammunition round includes a cartridge case (9), a primer (14), a propellant charge (15), and the hollow core projectile (10) (30) and, in addition, an abturator (12) and a pusher (11) interposed between the projectile (10) (30) and propellant (15).

Description

Small Arms Ammunition

Rationale of the Invention

While the present invention is of general application to all forms of small arms ammunition, the basic mode of same was developed in connection with a program to improve the accuracy and effectiveness of low velocity hand guns particularly the M1911A1 caliber .45 US pistol and hence the generic concepts of this inven- tion and one preferred embodiment set forth herein will be described in association with a discussion of this weapon. However, as will be readily appreciated by those of ordinary skill in the art, the concepts for improvement of ammunition herein disclosed are fully applicable to all forms of small arms ammunition including rifle ammuniition. A preferred mode of the invention herein described is especially applicable to small arms capable of firing a projectile at velocities exceeding Mach 1.9. The M1911A1 caliber .45 US pistol although generally viewed as an inaccurate weapon when the same is employed by the average soldier is a structurally sound weapon. Firing this pistol launches a standardized projectile, weighing 230 grains at approximately 860 ft/sec muzzle velocity. Since large quantities of this weapon have been produced, distributed and stockpiled, it would be highly advantageous to maintain the weapon in its current form, and employ the standard cartridge case and primer, yet improve the performance of the weapon. An improvement can be accomplished while retaining or increasing the kinetic energy delivered to the target, through use of a superior projectile form. The weapon's accuracy may well be increased as well. While numerous studies have been directed to the M1911A1 caliber .45 US pistol, these studies have tended to place more emphasis on the weapon's functional characteristics than on the projectile employed therewith.

Further, biophysics or wound ballistic testing and analysis revealed that the standard caliber .45 projectile did not deposit a great amount of its kinetic energy upon hitting an unprotected (normal clothing) individual. Thus, although the projectile made a relatively large wound track, the projectile would not expend sufficient energy within the human target media and hence exits the target with a reasonable amount of energy being retained by the projectile. Additionally, recent testing has also shown that the new Kevlar TM body armor will prevent the standard .45 caliber projectile from penetrating both the Kevlar TM material and the body, even when the projectile impacts at muzzle velocity. The standard caliber .45 projectile also cannot penetrate the new U. S. Army Kevlar ^TM fiberglass helmet.

While detailed information about the interaction of the weapon's components and the effectiveness of the projectile fired therefrom are now known none of the studies made on the .45 U.S. pistol have led to improvement in the weapon's accuracy and its wound ballistic capability in the hands of the average soldier.

A similar situation exists with regard to the 9 mm pistol and to hand guns employed by police forces. Thus, the .38 special is a revolver that has been shown to lack high muzzle velocity effectiveness against body armor, and overpenetration of an unprotected target. By contrast, the .357 magnum is a more powerful police weapon firing a lead bullet at approximately 1,220 ft/sec, but the projectile of the .357 magnum may overpenetrate the target to such a degree that bystanders behind the target might be wounded or even killed. These particular revolver designs have been manufactured in large quantities and these weapons will continue to be produced, distributed and used. It would be extremely advantageous to utilize these revolver weapons in their present form without modification thereto, yet provide a significant increase in their overall terminal effectivenesss, without also increasing key system performance factors, such as the recoil.

By providing a unique projectile geometry which maximizes both inflight stability and terminal effectiveness as well as reduced time of flight to useful ranges, it has been found possible to achieve a significant gain in overall small arms weapon performance. Therefore, it is an object of this invention to provide improved small arms ammunition capable of being employed in conventional weapons.

A further object of this invention is to provide small arms ammunition exhibiting markedly improved accuracy and effectiveness characteristics. An additional object of this invention is to provide improved small arms ammunition capable of muzzle velocity in excess of Mach 1.9.

Another object of this invention is to provide improved small arms ammunition exhibiting improved energy deposit characteristics in unprotected target media.

A further object of this invention is to provide improved projectiles for small arms ammunition capable of penetrating currently available body armor. An additional object of this invention is to provide improved small arms ammunition exhibiting markedly reduced recoil characteristics vis a vis conventional ammunition.

Other objects and advantages of the present invention will become clear from the following detailed description thereof. Summary of the Invention

The improved small arms ammunition of this invention comprise a conventional primed cartridge case and a hollow projectile means of tubular geometric form. The projectile means includes a main body tubular portion of diameter corresponding to the caliber of the weapon, e.g., 9 mm, .45 caliber, .357 caliber, etc. and a lesser outside diameter annular nose end of circular cross-section; the nose portion tapers down from the juncture thereof with said main body portion to the nose end of the projectile. The main body portion may have a rotational band around at least a portion of the periphery thereof. In the ammunition the hollow portion of the tubular projectile is backed by means for sealing off the tubular hollow through the projectile so that propulsive force from the propellant may be imparted thereto. Ammunition rounds for pistols prone to jamming e.g., .45 caliber, 9 mm. pistols may include means for plugging the hollow portion of the tubular projectile. If the gun is capable of firing the projectile at velocities greater than Mach 1.9 a preferred projectile geometry such as is hereinafter described may be employed advantageously.

Brief Description of the Drawings The invention will be more clearly understood by the following detailed description of exemplary embodiments thereof which is posed in conjunction with the accompanying drawings in which:

Figures 1A-1C illustrate a conventional caliber .45 ball round according to the prior art wherein

Figure 1A is a sectional view showing the round in an assembled condition. Figure IB is a sectional view showing the details of the primed cartridge case, and Figure 1C is a sectional view showing the details of the caliber .45 ball projectile; Figure 2 is a sectional illustration of a preferred embodiment of the improved small arms ammunition according to the present invention adapted to the .45 caliber pistol; Figures 3A and 3B illustrate details of an exemplary tubular projectile means adapted for use in small arms weapons capable of achieving a muzzle velocity of less than Mach 1.9 wherein Figure 3A is a sectional side view of the tubular projectile and Figure 3B is a front view thereof;

Figures 4A and 4B illustrate the details of an exemplary pusher disc adapted to the embodiment of the invention shown in Figure 2, wherein Figure 4A is a front view of the pusher disc and Figure 4B is a side view thereof;

Figures 5A and 5B illustrate the details of an exemplary obturator means adapted to the embodiment of the invention shown in Figure 2, wherein Figure 5A is a front view of the obturator means and Figure 5B is a side view thereof; and

Figure 6 is a side view showing the pusher disc of Figures 4A and 4B mounted within the obturator means shown in Figures 5A and 5B.

Figure 7 is a sectional diagrammatic side view of the projectile of Figures 3A, 3B assembled with an obturator, a pusher disc, and a nose plug.

Figure 8 is a sectional side view of a mode of projectile adapted to supersonic muzzle velocities exceeding Mach 1.9. Figure 9 is a sectional diagrammatic view of the projectile of Figure 8 assembled with a pusher disc and an obturator sabot.

Detailed Description of the Invention Referring now to the drawings, particularly to Figures 1A-1C thereof, shown there is shown a conventional round of ammunition (a caliber .45 ball round). As will be readily appreciated by those of ordinary skill in the art, the conventional ammunition illustrated in Figure 1A comprises a primed cartridge 1 having a projectile 2 disposed therein. The primed cartridge is separately illustrated in Figure 1B while the projectile is best shown in Figure 1C. The primed cartridge 1 has a primer 3 disposed at the rear of the casing so that the ammunition round may be fired upon striking of the primer 3 by- the weapon's firing pin. The round is provided with suitable propellant 4 disposed within the primed cartridge 1 intermediate projectile 2 and primer 3.

The projectile 2 employed within the conventional caliber .45 round actually illustrated in Figure 1A, weighs approximately 230 grains and has a lead alloyed core 5 about which is disposed gilded metal jacket 7 generally made of copper or the like. Firing of the conventional caliber .45 round illustrated in Figure 1A launches the projectile at approximately 860 ft/sec from a primed casing containing approximately 5 grains of propellant.

The standard projectile of the .38 special weighs 158 grains and is launched at approximately 900 feet per second muzzle velocity by approximately 3.5 grains of propellant. The conventional caliber .357 ammunition utilizes approximately 3.5 grains of propellant to launch a projectile weighing approximately 158 grains at about 1,250 feet per second.

As has already been indicated, the standard caliber .45 pistol and the .38 Special hand gun projectiles described above and others like them, such as the 9 mm. hand gun will not penetrate Kevlar TM armor and mostly do not efficiently deposit their kinetic energy i.e.,

"energy dump" within a human target. The .357 magnum projectile is also inefficient with regard to "energy dump" in the target. Referring now to Figure 2 there is shown in sectional view an exemplary embodiment of the improved small arms ammunition according to the present invention. Although the mode of Figure 2 is adapted to low velocity projectile purposes, e.g., a caliber .45 round, all modes of the improved small arms ammunition round of this invention include the components illustrated in Figure 2, namely a primed cartridge 9, tubular projectile means 10, pusher disc 11, obturator means 12, primer 14, and propellant 15. In addition, the ammunition round includes a means element 21 to ensure that the projectile 10 becomes rotated by the lands and grooves in the gun barrel.

The primed cartridge 9 may take identically the same form and size as that employed in a conventional caliber projectile e.g., as in the caliber .45 ball round illustrated in Figure IB and hence is provided with the same primer and often the same quantity of propellant. For best results, the charge selected for propellant 15 should be faster burning than the conventional propellant 4 due to the lighter weight of the projectile of .this invention. Faster burning propellants are commercially available as for example, the propellants sold under the marks "Bulls Eye" and "Red Dot" by the Hercules Powder Company; selection of the propellant type forms no part of this invention.

The tubular small arms projectile 10 of this invention is best shown in Figures 3A and 3B wherein Figure 3A is a sectional side view of tubular projectile 10 and Figure 3B is a front view thereof. The projectile 10 will have a diameter D which corresponds to the diameter of the standard projectile 2 illustrated in Figure 1C for the intended weapon which dimension for the 0.45 caliber pistol corresponds to .450 inches. A copper band 21 fixed to the periphery of projectile 10 cooperate with the lands and grooves of the gun barrel to rotate the projectile. The length of the tubular projectile 10 is preferably such that the projectile length to diameter ratio may be as low as approximately 1.5 to 1; however, as will be readily appreciated by those of ordinary skill in the art, this ratio may be varied greatly and be coupled with a variation in the diameter of the hollow core 17 of the projectile to provide optimum projectile mass. Unfortunately, cartridge case length and associated volume are limited in the military hand gun cartridge cases, particularly in the caliber .45 and 9 ram. pistols, making projectile velocity too low to take full advantage of projectile geometry best suited to travel at supersonic velocities.

In military pistols such as the caliber .45 and 9 mm pistols, the rounded front end of the projectile allows for effective feeding of a round into the firing chamber. Figure 7 illustrates a mode of the invention adapted to retain an appropriate rounded off front end contour in the round. A loosely fitting plug 101 with a contoured nose made from a plastics material is included to round of the nose end 18 of the ammunition round. On firing the round illustrated by Figure 7, when the projectile 10 leaves the muzzle of the weapon pusher 11, obturator 12 and nose plug 101 are separated from projectile 10 to the rear thereof by the relative drag forces arising when the projectile freely flies toward the target.

Thus far, this invention has been described in terms of a low muzzle velocity embodiment thereof. Low velocity, as employed herein, is intended to refer to muzzle velocities below Mach 1.9. For low velocity modes of this invention, the shape of hollow core 17 may be geometrically simple, e.g., a core made in the form of a cylinder as is illustrated in Figures 2 and 3. In addition, the rear end shape of projectile 10 may be selected for manufacturing convenience, as for example, the stubby non-boat-tailed terminus illustrated in Figures 2 and 3. On the whole, projectile shape and size may be determined by extrinsic characteristics such as the cartridge case length of existing pistols, or a need to prevent jamming in the pistol. However, regardless of design compromises made in low velocity modes of projectile such as has been described above, all modes of this invention exhibit certain important advantages over the hitherto standard (solid) projectiles. They pierce the Kevlar ^TM body armor; they exhibit a greater level of "energy dump" in the target; and, recoil is reduced.

High Muzzle Velocity Embodiment

Contemplated within practice of this invention is a mode of projectile expressly intended for the ammunition used in weapons capable of generating muzzle velocities exceeding Mach 1.9.

For such ammunition, the configuration of the tubular projectile may be shaped to take advantage of the isentropic equations relating to the inlet and throat areas of the hollow core in the projectile.

This, in turn, produces a low aerodynamic drag which cannot be achieved with the low velocity projectiles.

Many hand gun cartridge cases, particularly those for revolvers and shoulder-fired weapons, have much larger volume than the caliber .45 and 9 mm cartridge cases. Such cartridge cases can thus accommodate more propellant and a longer projectile fits the firing chamber of such weapons, allowing thereby employment of a high velocity mode of hollow projectile with advantages over the low velocity hollow projectile mode (of Figure 3) . In particular, the hollow projectile intended for the .38 special and .357 magnum can be extended longitudinally vis a vis the .45 caliber projectile to increase projectile mass and ballistic coefficient, and can be given more aerodynamic shaping to further reduce drag. A thinner projectile has lower projected area, handles airflow better, particularly at velocities above Mach 1.9, and results in lower drag.

A low drag shape projectile is particularly applicable to longer barrel handguns and to both sporting rifles and shoulder-fired military weapons, since all these weapons have sufficient cartridge case volume to produce muzzle velocities above Mach 1.9.

The isentropic equations derived for supersonic flow entering an inlet duct or tube as for example, the equations utilized for air inlet designs for jet engines can be applied to design of a tubular projectile having low aerodynamic drag. The equations provide basis for establishing the ratio between the area in the throat of the tubular core and the area at the inlet entrance to core. Simply stated, an area ratio below about 0.5 to 1 will not result in efficient flow into and through the hollow core. An area ratio below 0.5 to 1 causes the air in front of the projectile to compress into a standoff shock wave and then a portion of the air behind the shock wave flows around the outside of the projectile rather than through the core. This flow effect markedly increases the drag and is known as "choking." By presence of a proper area ratio the "choking" effect can be avoided initially and then be delayed until the projectile has reached the lower Mach number predicted by the equations. Use of an area ratio in excess of about 0.5 to 1 generates a lower aerodynamic drag configuration and results in an aero- dynamically more efficient projectile.

Within the context of this invention the term high velocity tubular projectile is intended to refer to those projectiles the weapon at muzzle velocities exceeding Mach 1.9. To launch a tubular projectile and initially avoid "choked" flow, requires a Mach number above Mach 1.9. The commercial cartridge cases available for revolver hand guns and shoulder-fired weapons have sufficient length to allow for aerodynamic shaping of the tubular projectile and have enough remaining volume for propellant so that the ballistic properties of the propellant charge can be matched to a lightweight high velocity tubular projectile.

In a preferred embodiment of the present invention aerodynamics and ballistics considerations have been utilized to create a hollow or tubular high velocity projectile of much lighter weight than the standard projectile, such as has been used heretofore in either the .357 magnum, or in shoulder-fired weapons.

Referring now to Figure 8, it may be seen that the high velocity projectile 30 is formed with a boat-tail rear end 32, a length (L) to diameter (D) ratio in the range of about 1.5 to 2.5 to 1, preferably 2.0-2.5 to 1, and an internal conical taper 34 in the core extending from inlet 40 to throat 38. An external conical taper or slant 36 in the nose portion 37 remains.

Conveniently the circular front end edge of the projectile lies on the median circumference cylinder of tubular projectile 30 and the internal and external taper leading back from the front end edge are at the same angle to the median circumference cylinder. The internal diameter (d) at throat 38 inside body portion 39 is related to the circular inlet diameter (D) at the nose end inlet 40 to provide a throat to inlet area ratio above about 0.5 to 1. An internal taper 41 is provided also at the rear of the hollow core; the rear end taper 41 need not be at the same angle as the front end internal taper, and bears no relation to the boat-tailing external contour at the rear end of projectile 30. The combined angle in the nose portion 37 may be selected in the range of from 8° to 25° and more specifically be within a preferred range of 10° to 20°. In an exemplary embodiment of the projectile mode of Figure 3 which was built and tested, the leading edge angle was approximately 17 1/2°; the same included angle may be employed for the projectile mode of Figure 8.

The Ammunition

Since the hollow tubular projectiles 10 and 30 will usually be fabricated from hard material such as steel or the like, it is desirable to have a softer, more ductile material, copper, for example, formed into a rotational band around at least a portion of the main body of the projectile, as is illustrated, for example, on Figure 3 and Figure 8 by presence of rotational bands e.g., band 21 on main body 20 on the mode of Figure 3. Rotational band 21 provides the requisite engraving to fit the rifling in the pistol barrel and acts to transmit the torque resulting from engagement with the barrel's lands and grooves to the hollow tubular projectile 10 as the projectile traverses the barrel of the weapon to rotate the projectile and hence give gyroscopic stability to tubular projectile 10. If conventional copper material is employed for the rotational band 21, the same may be affixed to the main body portion 20 of the tubular projectile 10 by known to—the-art techniques such as swaging, flame spraying, or welded overlay processes. The selection of the rotating band material together with the attachment process forms no part of this invention, and is dictated by economic and fabrication considerations. Presence of a hollow core through the tubular projectiles 10 and 30 of this invention requires the assembled round to include components not normally part of a conventional round, namely, a pusher disc such as, for example, the pusher disc illustrated by Figure 4A, 4B and an obturator such as the obturator illustrated by Figure 5A and 5B. The structure of the pusher disc 11 and obturator 12 employed in the ammunition of this invention is best shown in Figures 4A and 4B which illustrate front and side views thereof, respectively. The pusher disc 11 may be made of steel, plastic, or any relatively hard material structurally compatible with the other materials employed for the tubular projectiles 10 and 30. The function of the pusher disc 11 is to transmit the propulsive force generated by burning propellant 15 to the tubular projectiles 10 and 30 and hence to effectively seal off the hollow core until such time as the tubular projectile has exited the barrel of the weapon, and the full force of the propellant charge 15 is no longer applied thereto. The pusher disc bears upon the surface area at the rear of the tubular projectile and is adapted to seat in an obturator 12 such as shown in Figures 5A and 5B.

An obturator 12 embodiment contemplated for the improved small arms ammunition is shown in Figures 5A and 5B which illustrate front and side views, respectively, thereof. The obturator 12 seals off the burning and expanding propellant gases engaging the lands and grooves in the barrel during travel down the barrel so that the full force of the propellant gases as well as gyroscopic stability is imparted to obturator, pusher disc and projectile as a single unit. The obturator 12 is usually fabricated from a suitable plastic material such as polyethylene, although any suitable ductile material exhibiting acceptable cost, strength, and fabricating characteristics may be employed. The obturator 12 contains a front side face 23 that acts as a seat for the pusher disc 11, as is shown in Figure 6. Suitably, obturator 12 has flanged periphery to provide a peripheral portion with a relatively wide surface for engaging the lands and grooves in the barrel. However, it should be noted that rear side face 24 of the obturator 12 need not be configured the same as the front side 23 since the front side is configured as a seat for the pusher disc 11, while the rear side face 24 of the obturator means 12 is configured to receive the propulsive forces of the expanding propellant and to be a distribution surface for the expansive force of the propellant and to apply same to the tubular projectile.

Referring now to Figure 6, shown there is a side view of how pusher disc 11 ^"seats within the obturator means 12, the depth of the seat for pusher disc 11 within the front side 23 of obturator 12 being such that the periphery of the obturator 12 extends past the front face of pusher disc 11. Thus, obturator 12 is specially adapted to fit properly around the rear end section of the tubular projectiles 10 and 30.

If desired, the obturator function may be combined with the rotational band function into a sabot, as is illustrated in Figure 9 by an obturator 102 that contains a peripheral flange thereon that extends forward around the projectile 30. With such an obturator no need exists to provide a rotational band at the outside of the tubular projectile.

Referring again to Figure 2, it will be seen that the improved small arms ammunition of the present invention is assembled by loading a conventional primed cartridge 9, with more or less the same amount of propellant as is used for a conventional projectile, albeit that the propellant should have burning properties better suited to the lighter, tubular projectile. Thereafter, the tubular projectile 10, or 30, prefitted snugly to the pusher 11 and obturator 12 at the rear of the projectile is then inserted into cartridge case 9 (and crimped therein). In the mode of Figure 7 plug 101 is inserted first. The complete round of ammunitionis then ready for firing from a weapon. In an exemplary embodiment of the low velocity mode of the invention (i.e., the mode of Figure 2) which was built and tested, the tubular projectile 10 weighed approximately 95 grains and was made of steel; affixed to the main body portion 20 was a copper rotational band 21 with a thickness of .015 inches nominal. In this embodiment, the diameter of the hollow core 17 was approximately .297 inches nominal and the thickness (T) of the steel walls at the main body portion 20 was .0616 inches nominal. The angle employed for the aslantly disposed surface 19 was 17.5°, while the length L of the main body portion was .434". The addition of pusher 11 and obturator means 12 , as illustrated in Figure 6, adds approximately 14 grains to the mass that must be moved up the barrel. When the trigger of the loaded weapon is pulled, the firing pin strikes the primer 14 which then ignites the propellant 15. The burning propellant 15 creates pressure which acts on the rear surface 23 of the obturator means 12 and produces the force that initiates the movement of the pusher 11, obturator means 12 and tubular projectile 10 as an integral unit up the barrel toward the muzzle.

The resulting force causes the pusher 11 and obturator means 12 and the tubular projectile means 10 to move as a unit, up the barrel. This initial motion also brings the rotational band 21 on the projectile into engagement with the barrel's grooves so that the pusher 11 and obturator means 12 and the projectile 10, commence rotation as a unit when translation up the barrel occurs.

Then upon exiting at the muzzle, the drag force from air flow through the hollow core portion of the tubular projectile 10, the air flow about the rear of the unit and the base pressure generated, act in combination to separate the relatively light pusher 11 and obturator 12 from the tubular projectile 10 and to force nose plug 101, if present, out through the rear of the projectile. The spinning tubular projectile 10 is thus freed in its trajectory and is gyroscopically stable. This stability, together with the sharp nose design of the projectile, has been proven to be an effective penetrating missile for both unprotected and body armor protected targets.

When considered from the standpoint of accuracy, the caliber .45 weapon has always had a rather varied reputation because the average user does not generally obtain good results with this weapon due principally to the rather large and infamous recoil associated therewith. However, when employed with the improved small arms ammunition according to the present invention, impulse or recoil from firing the tubular projectile means 10 is reduced by approximately 20 percent from that associated with firing conventional rounds even though the muzzle velocity for the tubular projectile is in a range of 1200 to 1300 ft/sec, almost half again the muzzle velocity of a conventional round. Thus, while the muzzle velocity of the improved round is markedly increased over that available with conventional rounds, the lighter tubular projectile 10 results in a markedly reduced impulse or recoil from the weapon because momentum transfer or recoil is a function of the projectile mass multiplied by the velocity. The reduced impulse or recoil should then allow the average user to achieve increased accuracy while the marked increase in muzzle velocity results in a significant increase in the effectiveness of the system when viewed from the standpoint of wound ballistics.

In addition, the higher flight velocity of thetubular projectile 10 when coupled with the sharp leading. edge geometry and the hardness of the tubular projectile 10, together with the gyroscopic stability associated with projectile rotation produces a terminal ballistics effectiveness unmatched by a conventional ball round against either protected or unprotected targets. In the exemplary embodiment of the invention according to, the mode of Figure 8 sized to fit the .357 magnum which was built and tested, the tubular proejσtile weighed approximately 57 grains and was made of steel having a copper rotating band affixed to the main body portion. In this embodiment the throat diameter "d" of the hollow core was approximately .197" nominal and the thickness of the steel walls of the main body portion was .079" nominal.

When considered from the standpoint of target effects, the .357 handgun has always had a good reputation for its terminal effects upon general targets. However, when this weapon is employed with the improved small arms handgun ammunition according to the present invention, impulse or recoil when firing the tubular projectile is reduced between 15 to 20 percent from that associated with firing conventional projectiles even though the muzzle velocity for the tubular projectile is in the range of 2100-2300 ft. per second or approximately 850 ft. per second greater than the muzzle velocity of the conventional round. The reduced impulse or recoil should then allow the average user of the .357 magnum and the user of the .38 Special to achieve increased accuracy and the increase in muzzle velocity results in a sharp gain in the effectiveness of the projectile system from the standpoint of wound ballistics.

The low drag shaping employed in the high velocity projectile mode shown in Figure 8 causes the velocity decay of the lighter weight lower ballistic coefficient tubular projectile to be comparable to or better than the velocity decay characteristics of a standard .357 projectile. The invention herein has been described in terms of military and police handguns, weapons for which the tubular projectile means 10 and 30 are preferably fabricated from a hard and tough material such as steel, or high density materials, such as powder alloys, or various types of high strength composite materials.

Biophysics testing revealed that the hard material of the tubular projectile means coupled with the sharp leading edge formed by the circular nose 18 does not exhibit the mushroom characteristic of hollow-point or dum-dum bullet in that the projectile does not mushroom or deform, but maintains its shape while penetrating body armor and/or body tissue simulant. If desired, however, soft nose materials may be employed for the tubular projectile.

As has already been pointed out, practice of this invention is applicable to rifles, for which weapons the high velocity projectile mode of Figure 8 is preferred. However, in a hunting rifle mode of ammunition fabricating projectile 30 from a soft metal is a preferred mode, although manifestly hard metal projectiles should be employed in military or police weapons. Moreover, the tubular projectiles might well be formed from non-metallic materials if advantageous for some specific applications. While this invention has been described in connection with a preferred exemplary embodiment thereof, it will be understood that many modifications will be readily apparent to those of ordinary skill in the art; and that adaptations and variations thereof are contemplated herein.

For instance, rather than employing the rotational band disclosed, the outside of the tubular projectile means may be gilded, and integral pusher disc and obturator means may be employed, as may combined rotating band and obturator (such as is shown by

Figure 9). Varying dimensional changes in the projectile may be implemented without significant deviation from the concepts taught herein.

Claims

What is claimed is:

Claim 1 - Small arms ammunition comprising: a primed cartridge case means; a hollow tubular projectile formed of a cylindrical main body portion and a nose portion, said nose portion tapering down from said main body portion toward the apertured front end of said hollow tubular projectile, said main body portion being inserted within said primed cartridge case means with said nose portion extending therefrom; and, obturator means at the rear of the projectile sealing off the projectile from the propellant in said cartridge means.

Claim 2 - The small arms ammunition according to Claim 1 wherein said hollow tubular projectile means is formed of a hard metal.

Claim 3 - The small arms ammunition according to Claim 1 including on said projectile an internal taper extending from the front section of said nose portion to a throat in the body portion, and a boattail terminus on said projectile.

Claim 4 - The small arms ammunition according to Claim 1 wherein said main body portion of said hollow tubular projectile includes rotational band means fixed peripherally thereof, whereby upon launching of said tubular projectile means said rotational band means cooperating with lands and grooves within the barrel of a weapon to impart gyroscopic stability to said hollow tubular projectile.

Claim 5 - The small arms ammunition according to Claim 4 wherein said rotational band means is made of a soft, ductile material. Claim 6 - The small arms ammunition according to Claim 1 additionally comprising a pusher and obturator means snuggly fitted to the rear of said hollow tube projectile.

Claim 7 - The small arms ammunition according to Claim 6 wherein said pusher means is a flat circular disc seated in the obturator means between obturator and projectile.

Claim 8 - The small arms ammunition according to Claim 7 wherein said obturator means is in the form of a disc-like member having thickened peripheral portions, the front side of said obturator being arranged to seat said pusher disc means therein snugly to the rear of said hollow tubular projectile, said obturator having extended peripheral portions arranged to cooperate with lands and grooves within a weapon's barrel.

Claim 9 - A projectile for small arms ammunition which comprises a hollow tubular member having: a length to diameter ratio in the range of about 1.5 to 2.5 to 1; a cylindrical main body portion and a nose portion, said nose portion tapering down from said main body portion to the front end of said nose portion, and rotational band means on the periphery of said cylindrical main body portion.

Claim 10 - The projectile of Claim 9 wherein said projectile further comprises: an inner surface tapering from the front end of said nose portion to a throat region inside said cylindrical main body portion forming thereby an inlet at the front end of said nose portion which reduces toa more narrow throat through the hollow projectile, the ratio of throat cross-section area to nose inlet crosssection area being at least 0.5 to 1, said projectile terminating in an outside boat-tail and rear end taper in the hollow core that enlarges the outlet of said throat through the boat-tail.