Traceable Frangible Projectile
A frangible projectile useful in a round of gun ammunition wherein, upon striking a target, the projectile selectively disintegrates, leaving intact at least one portion or appurtenance of the projectile which is recoverable for purpose of identification of rifling markings thereon and/or other analysis.
This application claims the benefit of U.S. Provisional Application No. 60/949,101; filed Jul. 11, 2007.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTNot Applicable
FIELD OF INVENTIONThis invention relates to the tracing of a spent bullet (projectile) to the gun from which the projectile was fired. More particularly, this invention relates to the traceability of a frangible projectile to the gun from which such frangible projectile was fired.
BACKGROUND OF INVENTIONTraceability of a spent projectile to the gun from which it was fired is a major factor in criminology. Commonly a projectile designed to be fired from a gun comprises a soft metal jacket housing a frangible core. When such projectile is fired from a gun having a rifled barrel, the rifling internal of the barrel imparts a “signature” to the outer surface of the jacket as the projectile moves through and out of the barrel. In a fully frangible projectile, as opposed to a fragmenting projectile, there commonly is no part of the projectile which is recoverable and useful as enables a criminologist to identify any markings on the jacket which might be valuable in identifying the gun from which the projectile was fired.
Of recent, there has been introduced to the marketplace a projectile 10,
Referring to
Upon a frangible projectile as described above and depicted in
Ammunition comprising frangible projectiles also are desirable in that they do not contain undesirable lead metal. In certain quarters, this ammunition is termed “green” ammunition in that it does not introduce lead to the environment. In particular, the ammunition which employs these frangible projectiles is desired by both military and civilian defense forces for the reasons, among others, that once the projectile strikes a solid or hydraulic target (such an animal or human being), the fast spinning projectile substantially disintegrates into minute individual particulates which either do not exit the target, or if they do exit the target, their momentum very quickly reduces to a harmless velocity. Due to their frangibility, these projectiles do not ricochet at approach angles as small as about 15 degrees.
However, these fully frangible projectiles do not leave intact any portion of the projectile which is useful for identifying rifling markings thereon, if any.
SUMMARY OF INVENTIONAccording to one aspect of the present invention, the present inventor provides a frangible projectile useful in a round of gun ammunition wherein, upon striking a target, the projectile selectively disintegrates, leaving intact at least one portion or appurtenance of the projectile which is recoverable for purpose of identification of rifling markings thereon and/or other analysis thereof.
In one aspect of the present invention, the inventor provides for structuring the projectile to include a disintegration-limiter factor which establishes selective disintegration of the projectile when the fired projectile strikes a target, while also providing for a selected portion of the projectile bearing rifling marking to remain intact upon striking the target. This structuring of the projectile may take the form of structural design of the jacket in the region thereof most adjacent the trailing end thereof or, in another embodiment, it may take the form of incorporation into the projectile of an appurtenance which takes on indentifying rifling marking as the projectile passes through the rifled barrel of a gun and which survives intact upon disintegration of the core upon the projectile striking a target.
The disintegration-limiting factor may take on several forms, but in each form, the projectile is designed to disintegrate upon striking a target, such disintegration commencing at the leading end of the projectile and promulgating toward the trailing end of the projectile. Such limiter factor may be formed integrally of the jacket and/or may be in the form of an appurtenance supplied to the frangible core of the projectile. Such limiter factor effectively either retards or halts the promulgation of disintegration of the core and resultant intact survival of at least an appurtenance or a portion of the projectile disposed proximate the trailing end of the projectile, resulting in preservation of an intact recoverable portion of the projectile having rifling markings thereon.
In accordance with one aspect of the present invention there is provided a round of ammunition 11 comprising a projectile 10 (see
Variations of the present projectile are depicted in
At the outset and by way of example, it will be recognized that a projectile fired from 30-06 caliber rifle having a 1 in 10 twist will exit the rifle muzzle at about 2900 ft/sec and will rotate about its longitudinal centerline at about 208,000 rpm over a distance of at least 200 yards, for example. At this velocity and rate of rotation, disintegration of the projectile upon striking a target will occur over a period of time measured in nanoseconds. Accordingly, it is further to be recognized that the total disintegration discussed herein takes place over a time period of a few nanoseconds. Irrespective of this time factor, the present inventor has found that the alteration of the disintegration of the projectile along its length as provided by the present invention can be varied over a wide range of values by a wide range of techniques employing a disintegration limiter factor, to produce dramatic terminal ballistics upon the projectile striking a target, such as a standard gel block commonly employed in the industry for visually demonstrating the terminal ballistics of a projectile fired from a gun.
A typical frangible projectile of the prior art is depicted in
With reference to
With further reference to
In this embodiment, the increase in the wall thickness of the jacket may commence at a location 24 about midway between the leading and trailing ends of the jacket, and preferably at a location between the trailing end of the jacket and the midway location 24 between the leading and trailing ends of the jacket. In one embodiment, the wall thickness of the jacket is gradually increased from a minimum wall thickness proximate the midpoint between the leading and trailing ends of the projectile, to a maximum wall thickness proximate the trailing end of the jacket. In one embodiment the wall thickness of the jacket proximate the trailing end of the projectile may be about twice the wall thickness of the jacket at approximately the midpoint between the leading and trailing ends of the jacket.
With reference to
With reference to
Another embodiment of the present invention is depicted in
In this embodiment, the outer diameter of the ring is chosen to be slightly greater than the outer diameter of the projectile so that as the projectile passes through the rifle barrel, the outer circumferential surface of the ring is imprinted with the rifling markings of the barrel.
In this embodiment of
In
In this embodiment, that end of the core 18′ adjacent the trailing end of the projectile is provided with a cup-shaped cap 60 of soft metal, tin for example, which overwraps the trailing end of the projectile and extends therefrom up and about the outer surface of a substantial portion of the core 18′. The outer surface 61 of that portion of the cap which surrounds the core 18′ becomes imprinted with the rifling markings of the gun barrel from which this projectile is fired.
In this embodiment of the present invention, there are two limiter factors, the first being the junction 63 of the two cores 18 and 18′ and the second being the rim 64 of the cap fitted over the trailing end of the projectile. When the projectile of this embodiment strikes a target and disintegrates, the result is a flattening out of the cap, but without disruption of the rifling pattern on the outer surface of the cap so that the cap remains intact to the extent needed for identification of the rifling markings on the cap upon recovery of the intact cap from the target.
The further embodiment of the present invention depicted in
Whereas the term “gun” has been employed herein for convenience purposes, it is to be understood that the projectile of the present invention most commonly is of the type which is suitable for being fired from a rifle or a pistol having a barrel which includes rifling interiorly of the barrel.
While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the invention to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept. For example, It will be understood by one skilled in the art that the projectile of
Claims
1. An ammunition projectile adapted to be fired from a gun having a rifled barrel comprising
- at least one frangible powder-based core having a leading end and a trailing end and at least one portion of the projectile capable of being marked by the rifling of the barrel of the gun from which the projectile is fired,
- said core disintegrating into individual particulates upon the projectile striking a target, said disintegration commencing at the leading end of the projectile and propagating along the length of the projectile,
- at least one limiter factor disposed along the length of the projectile in the path of the propagating disintegration of the projectile,
- said limiter factor at least momentarily abating said propagation of said disintegration whereby at least said at least one portion of the projectile which is capable of being marked by the rifling of the barrel of the gun from which the projectile is fired becoming separated from the projectile intact and recoverable for analysis.
2. The ammunition projectile of the claim 1 wherein said at least one core comprises at least one powdered metal compacted into a self-supporting compact.
3. The ammunition projectile of claim 2 wherein said at least one core comprises at least first and second metal powders and a matrix comprising a polymeric material.
4. The ammunition projectile of claim 1 where said projectile comprises at least two individual cores disposed in stacked relationship to one another.
5. The ammunition projectile of claim 4 wherein said at least two individual cores are housed within a cup-shaped jacket.
6. The ammunition projectile of claim 1 wherein said limiter factor comprises at least one of
- (a) a jacket having a leading end and a trailing end and is of a materially thicker wall thickness from a location about midway between the leading and trailing ends of the jacket and the trailing end of the jacket,
- (b) a jacket having a cannelure defined about the outer circumference of said jacket at a location between the leading and trailing ends of the jacket,
- (c) a jacket having at least two cores disposed therein in stacked relationship to one another, and a disc interposed between adjacent ones of said at least two cores,
- (d) a jacket having a leading first end and a trailing second end and a internal circumferential shoulder dividing said first and said second ends into first and second portions, said second portion having a materially greater wall thickness than the wall thickness of said first portion,
- (e) first and second compacted powder based cores disposed in stacked relationship to one another, said first core including a trailing end having a blind bore defined therein and said second core including a leading end and a projection projecting from said leading end and adapted to be snugly engaged within said blind bore,
- (f) first and second compacted powder based cores disposed in stacked relationship to one another, and a ring of metallic material interposed between the adjacent ends of said stacked cores, a projection extending from one of said adjacent ends in the direction of the other of said cores, said ring encircling said projection,
- (g) first and second compacted powder based cores disposed in stacked relationship to one another, said first core including a trailing end having a blind bore defined therein and said second core including a leading end and a projection projecting from said leading end and adapted to be snugly engaged within said blind bore, said second core having a trailing end and a cup-shaped cap overlying said trailing end and extending partway along the outer surface of said second core in a direction toward said first core,
- (h) first and second compacted powder based cores disposed in stacked relationship to one another, said first core including a trailing end having a blind bore defined therein and said second core including a leading end and a projection projecting from said leading end and adapted to be snugly engaged within said blind bore, and including at least one elongated strip of a metallic material mounted on the outer surface of said cores and extending substantially along the length of said stacked cores. and,
- (i) a jacket having a leading first end and a trailing second end and an internal circumferential shoulder dividing said first and said second ends into first and second portions, said second portion having a materially greater wall thickness than the wall thickness of said first portion and including a substantially rigid disc embedded within the core at the location of the internal circumferential shoulder.
Type: Application
Filed: Feb 11, 2008
Publication Date: Aug 26, 2010
Inventor: Harold F. Beal (Rockford, TN)
Application Number: 12/029,136