GB2092274A

GB2092274A - Projectiles

Info

Publication number: GB2092274A
Application number: GB8102734A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-01-29
Filing date: 1981-01-29
Publication date: 1982-08-11

Abstract

A munition projectile having a relative density of between 1 and 8 is formed by injection moulding a composition comprising coarse metallic particles (30 to 75 mesh) bonded together with a plastics base material, the proportion of metallic material relative to the plastics base material being at least 150% by weight, and preferably being in the range of 150 to 900% by weight. The plastics material itself may be loaded with fine metallic particles (80 to dust mesh) to achieve relative densities at the upper end of the required range, and may be strengthened by the addition of steel, glass or carbon fibres.

Description

SPECIFICATION Munition Projectiles The relative density of a typical jacketed lead bullet is about 11. There is a demand, however, for lighter bullets having a relative density of between 1 and 8. With a relative density of between 1 and 3, for example, these lighter bullets might be used as practice rounds. With a relative density of between 5 and 8, the higher kinetic energies obtainable per given momentum would be suitable for specialised combat rounds particularly in automatic weapons.

Lighter bullets can be obtained by reducing the size of the standard bullets but this would involve redesigning the weapons with which the bullets are used because weapons are designed to give a momentum or about 19 to 22 foot pounds to the bullet as it emerges from the barrel.

Lighter bullets can also be made by using 'plastic' materials. The problem then is to achieve a bullet with sufficient density since even high density polyethylene has a density of only about 1. 'Plastic' bullets with a density of about 1 have only limited applications.

It has therefore been proposed to load a plastics material with a fine metallic powder in order to achieve the required higher relative densities. However, such heavy loading of a plastics material dilutes or diminishes the structural strength of the plastics material, and bullets made from such a composition are therefore likeiy to break up prematurely either in the barrel of the weapon firing the bullet or in flight.

In accordance with the present invention there is provided a munition projectile having a composition comprising coarse metallic particies bonded together with a plastics base material the proportion of metallic material relative to the plastics base material being at least 150% by weight, and preferably being in the range of 1 50 to 900% by weight. The plastics material itself may be loaded with fine metallic particles in order to achieve a composition having an even higher relative density. The resulting reduction in the tensile and impact strengh of the composition could be an advantage in those applications where it is desirable that the bullet should breakup on impact.

The fine particles preferably have a mesh size in the range of 80 to dust, while the coarse particles have a mesh size in the range of 3075, with the preferred ranges being respectively 100 to dust and 40to 65.

Examples of suitable plastics materials are high density polythene, an ethylene/vinyl acetate copolymer (EVA), and an acrylo nitryl/butadiene/styrene copolymer (ABS).

The metals or metallic compounds of which the particles are composed may not be the same for the fine and coarse particles. In particular, the coarse particles may be of lead to give the greatest possible weight, while the fine particles may be of a non-poisonous metal which homogenises with the plastics base and coats the coarse lead particles. The coarse particles might alternativeiy comprise copper or steel, for example.

Additional structural strength can also be obtained by adding elongate fibres to the composition, the fibres being formed, for example, of steel, glass or carbon and having lengths which typically lie in the range of 0.3 to 0.7 inches.

A feature of the invention is that a bullet formed from such a composition can be compression and/or injection moulded in a single stage process. Moreover, by varying the ratio of the constituent materials, bullets can be manufactured for a wide range of applications without changing the manufacturing process. For example, by suitably loading the bullet with fine metallic particles, a bullet can be manufactured to provide the same monentum as a conventional jacketed bullet but with greatly increased kinetic energy. It will thus provide substantially the same recoil momentum, and is therefore suitable for use in training rounds. The quantity of fine particles can also be adjusted to provide an intrinsically safe bullet with limited penetration and ricochet, or a frangible bullet which breaks up when it strikes a target.

The coarse particles provide the necessary structural strength for the bullet while the plastics base material bonds the particles together and provides the required overall density. A typical jacketed bullet weighs 11 5 grains and emerges from the barrel of a SMG at 1,250 feet per second. A bullet embodying the present invention may have a weight of 80 grains and emerge from the SMG at 2,000 feet per second.

In the accompanying drawings, Figure 1 is an energy/distance graph comparing the performance of a 9mm bullet embodying the invention (9mm PCA) with that of a conventional 9mm SMG bullet (9mm 2ZA), and Figure 2 is a trajectory drop/distance graph showing a similar comparison. The 9mm PCA bullet had a composition by weight consisting of 44% 60-30 mesh lead, 39% 100 mesh lead, 1 1% chopped glass, and 6% EVA plastics.

Claims

1. A munition projectile having a composition comprising coarse metallic particles bonded together with a plastics base Material, the proportion of metallic material relative to the plastics base masterial being at least 1 50% by weight.

2. A munition projectile according to Claim 1, in which the coarse particles have a mesh size in the range of 30 to 75.

3. A munition projectile according to Claim 2, in which the mesh size is in the range 40 to 65.

4. A munition projectile according to any one of the preceding Claims, in which the proportion of metallic material relative to the plastics base material is in the range of 1 50 to 900% by weight.

5. A munition projectile according to any one

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Munition Projectiles The relative density of a typical jacketed lead bullet is about 11. There is a demand, however, for lighter bullets having a relative density of between 1 and 8. With a relative density of between 1 and 3, for example, these lighter bullets might be used as practice rounds. With a relative density of between 5 and 8, the higher kinetic energies obtainable per given momentum would be suitable for specialised combat rounds particularly in automatic weapons. Lighter bullets can be obtained by reducing the size of the standard bullets but this would involve redesigning the weapons with which the bullets are used because weapons are designed to give a momentum or about 19 to 22 foot pounds to the bullet as it emerges from the barrel. Lighter bullets can also be made by using 'plastic' materials. The problem then is to achieve a bullet with sufficient density since even high density polyethylene has a density of only about 1. 'Plastic' bullets with a density of about 1 have only limited applications. It has therefore been proposed to load a plastics material with a fine metallic powder in order to achieve the required higher relative densities. However, such heavy loading of a plastics material dilutes or diminishes the structural strength of the plastics material, and bullets made from such a composition are therefore likeiy to break up prematurely either in the barrel of the weapon firing the bullet or in flight. In accordance with the present invention there is provided a munition projectile having a composition comprising coarse metallic particies bonded together with a plastics base material the proportion of metallic material relative to the plastics base material being at least 150% by weight, and preferably being in the range of 1 50 to 900% by weight. The plastics material itself may be loaded with fine metallic particles in order to achieve a composition having an even higher relative density. The resulting reduction in the tensile and impact strengh of the composition could be an advantage in those applications where it is desirable that the bullet should breakup on impact. The fine particles preferably have a mesh size in the range of 80 to dust, while the coarse particles have a mesh size in the range of 3075, with the preferred ranges being respectively 100 to dust and 40to 65. Examples of suitable plastics materials are high density polythene, an ethylene/vinyl acetate copolymer (EVA), and an acrylo nitryl/butadiene/styrene copolymer (ABS). The metals or metallic compounds of which the particles are composed may not be the same for the fine and coarse particles. In particular, the coarse particles may be of lead to give the greatest possible weight, while the fine particles may be of a non-poisonous metal which homogenises with the plastics base and coats the coarse lead particles. The coarse particles might alternativeiy comprise copper or steel, for example. Additional structural strength can also be obtained by adding elongate fibres to the composition, the fibres being formed, for example, of steel, glass or carbon and having lengths which typically lie in the range of 0.3 to 0.7 inches. A feature of the invention is that a bullet formed from such a composition can be compression and/or injection moulded in a single stage process. Moreover, by varying the ratio of the constituent materials, bullets can be manufactured for a wide range of applications without changing the manufacturing process. For example, by suitably loading the bullet with fine metallic particles, a bullet can be manufactured to provide the same monentum as a conventional jacketed bullet but with greatly increased kinetic energy. It will thus provide substantially the same recoil momentum, and is therefore suitable for use in training rounds. The quantity of fine particles can also be adjusted to provide an intrinsically safe bullet with limited penetration and ricochet, or a frangible bullet which breaks up when it strikes a target. The coarse particles provide the necessary structural strength for the bullet while the plastics base material bonds the particles together and provides the required overall density. A typical jacketed bullet weighs 11 5 grains and emerges from the barrel of a SMG at 1,250 feet per second. A bullet embodying the present invention may have a weight of 80 grains and emerge from the SMG at 2,000 feet per second. In the accompanying drawings, Figure 1 is an energy/distance graph comparing the performance of a 9mm bullet embodying the invention (9mm PCA) with that of a conventional 9mm SMG bullet (9mm 2ZA), and Figure 2 is a trajectory drop/distance graph showing a similar comparison. The 9mm PCA bullet had a composition by weight consisting of 44% 60-30 mesh lead, 39% 100 mesh lead, 1 1% chopped glass, and 6% EVA plastics. Claims

5. A munition projectile according to any one of the preceding Claims, in which the plastics material is loaded with fine metallic particles.

6. A munition projectile according to Claim 5, in which the fine metallic particles have a mesh size in the range of 80 to dust.

7. A munition projectile accordingto Claim 6, in which the fine particles have a mesh size in the range of 100 to dust.

8. A munition projectile according to any one of the preceding Claims, in which the composition further comprises elongate fibres of steel, glass or carbon.

9. A method of producing a munition projectile comprising injection moulding a composition comprising coarse metallic particles bonded together with a plastics base material, the proportion of metallic material relative to the plastics base material being at least 150% by weight.

10. A munition projectile according to Claim 1 and substantially as herein described.