GB2357137A

GB2357137A - Frangible projectile

Info

Publication number: GB2357137A
Application number: GB9929054A
Authority: GB
Inventors: Stephen Philip Dales
Original assignee: Gamebore Cartridge Co Ltd
Current assignee: Gamebore Cartridge Co Ltd
Priority date: 1999-12-08
Filing date: 1999-12-08
Publication date: 2001-06-13
Also published as: US20010007229A1; GB9929054D0

Abstract

A projectile 10 intended to be incorporated in a cartridge 38 for firing from a shotgun, for use by police forces and other law enforcement agencies as a means of rapidly breaking a lock or bolt holding a door closed, comprises a cylindrical low-strength casing 12, for example of paper, filled with a dense non - toxic finely divided material 32 such as tungsten powder. Whilst the projectile will retain its integrity until it strikes the target and thus will effectively blast a hole though a lock or bolt or through the portion of the door carrying such, the impact of the projectile with the target will fragment the paper casing allowing the tungsten powder to disperse rapidly so that after the powder has passed though the door against which the projectile is fired the powder will lose momentum within a very short distance due to atmospheric drag on the fine tungsten particles.

Description

2357137 PATENTS ACT 1977 Agents' Reference: P13732GB-MCC/ac

DESCRIPTION OF INVENTION

Title: "Frangible projectile" THIS INVENTION relates to frangible projectiles for firearms, that is to say to projectiles which will break up into a large number of individual particles on impact with a target but which projectiles will nonetheless retain their integrity until striking such target.

Various frangible projectiles have been proposed in the past, but these have commonly comprised metallic particles bound together by a binder, such as a plastics or other organic binder and the manufacture of such projectiles has involved the use of relatively complex moulding machinery, curing facilities, etc.

It is an object of the present invention to provide a frangible projectile which can be readily and cheaply manufactured and which is particularly suitable for use by police forces or other law enforcement agencies as a short range projectile for destroying door locks or bolts to secure rapid forced entry to premises.

According to the invention there is provided a frangible projectile comprising a closed low-strength case containing a charge of finely divided dense particles.

In a preferred embodiment, the case is made of paper and the dense particles comprise tungsten powder. In this preferred embodiment, not only does the 2 tungsten have the advantage of high density, but it has also the significant advantage, as compared with lead, for example, of being non-toxic.

Accordingly use of frangible projectiles in accordance with the preferred embodiment, poses less of a health hazard for police officers or other law enforcement personnel, in the course of practice and training in the use of such projectiles and less of a health hazard for them or for other parties involved in incidents where such projectiles may be used in earnest, whether criminals or innocent third parties. Likewise, premises where ftangible projectiles in accordance with the preferred embodiment are used are not contaminated with dispersed particles of toxic metal.

An embodiment of the invention is described below by way of example with reference to the accompanying drawings in which:

FIGURES 1 and 2 are perspective views from opposite ends of the frangible projectile embodying the invention; FIGURE 3 is a view in axial section of the projectile, and FIGURE 4 is a view in axial section of a cartridge incorporating the projectile.

The projectile 10 illustrated is intended to be fired from a large-bore, smooth bore firearm such as a shotgun and comprises a cylindrical casing of an external diameter appropriate to the bore of the firearm. The casing may, for example, be formed as a rolled paper tube 12 having the tube wall folded over across the diameter at one end to form a casing base 30. The interior of the casing is filled with a high density powdered granular material, such as tungsten powder, indicated at 32 in Figure 3, which is contained within the casing by a closure disc 34 fitting snugly within the casing at its upper end, the c) 3 above disc being retained by folding or rolling over the upper edge of the tube, the disc 34, inwardly onto the top of the disc 34 around the periphery thereof, as illustrated in Figure 3, in much the same manner as was customary for paper tube cartridges before these became almost universally replaced by plastics equivalents. Of course, the casing 12 of the projectile may be made in any convenient manner, although paper is the preferred material. Thus, for example, the tubular casing 12, after being filled with tungsten powder, can be closed at the upper end in the same way as it is closed at the lower, or both the upper and lower end could be closed by cardboard discs like the disc 34 retained by rolling over the edge of the tube onto the outer surface of the discs.

The projectile may be incorporated in a cartridge, as illustrated schematically, partly in side elevation and partly in axial section, in Figure 4, in which reference 38 indicates the tubular body of the cartridge proper, the projectile being illustrated as being accommodated within the front end of the cartridge which in turn is closed at its front end by a closure disc 40 retained within the front end of the cartridge tube 38 and retaining, within the cartridge, the projectile, a wad 42 behind the projectile and an explosive charge 44 behind the wad. The cartridge, apart from the projectile 10, is conventional.

The cartridge incorporating the projectile 10 is intended primarily for use by police forces and other law enforcement agencies as a means of rapidly breaking a lock or bolt holding a door closed, the main advantage of the projectile disclosed, as compared to more conventional projectiles in this context, being that whilst the projectile will retain its integrity until it strikes the target and thus will effectively blast a hole through a lock or bolt or through the portion of the door carrying such, the impact of the projectile with the target will fragment the paper casing allowing the tungsten powder to disperse rapidly so that after the powder has passed through the door against which the 4 projectile was deployed, the tungsten powder rapidly loses much of its momentum, through atmospheric drag, within a very short range and is thus less likely than conventional projectiles to cause personal injury or structural damage to persons or equipment within the premises to which entry is being effected. A further advantage, where tungsten powder is used, is that tungsten powder is non-toxic, unlike lead powder, for example, so that police officers or other personnel undergoing training or practice in the use of the frangible projectiles do not run the risk of inadvertently ingesting, e.g. by breathing, particles of toxic metal which might build up, over time, in their bodies.

It will be appreciated that other dense particles, apart from tungsten powder, may be used. However, tungsten is preferred because of its density nd non toxicity, and, for the specific purpose referred to above, finely divided powder is preferred in order to minimise the effective range of the contents of the projectile casing beyond the target at which it is fired.

In the present specification "comprise" means %ncludes or consists of' and "comprising" means %ncluding or consisting of'.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof

Claims

1. A frangible projectile comprising a closed low-strength case containing a charge of fmely divided dense particles.

2. A projectile according to claim 1 wherein the case is made of paper.

3. A projectile according to claim 1 or claim 2 wherein the dense particles comprise tungsten powder.

4. A cartridge, comprising a hollow tubular outer body, a propellant charge within the hollow tubular outer body, a wad within the hollow tubular outer body in front of the propellant charge, a projectile according to claim 1 being acconunodated within the hollow tubular outer body in front of the wad, and closure means at the front end of the hollow tubular body.

5. A frangible projectile substantially as hereinbefore described with reference to and as shown in the accompanying drawings.