GB2485166A

GB2485166A - A firearm stock

Info

Publication number: GB2485166A
Application number: GB201018499A
Authority: GB
Inventors: Rodney Goodman
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-11-02
Filing date: 2010-11-02
Publication date: 2012-05-09
Anticipated expiration: 2030-11-02
Also published as: GB201018499D0; GB2485166B

Abstract

A firearm stock (1) comprises a composite shell which is filled with a filling material. Specific areas (8,10) of the shell are filled with an energy absorbing substance to absorb the recoil of the firearm in use.

Description

A FIREARM STOCK

The invention relates to a firearm stock and particularly, but not exclusively, to a lightweight firearm stock with a recoil damping effect.

Traditionally, stocks for firearms have been made from wood, most commonly walnut.

Wooden stocks remain popular due to their aesthetic qualities, but suffer from a number of drawbacks. Given the importance of a secure fit for the action of the firearm, the tendency that wood has to warp over time, especially under the influence of temperature and humidity can be problematic. The wood must therefore be carefully selected and treated to ensure that the stock has sufficient strength and remains stable over time.

Many synthetic materials are inherently more stable than wood, and it has become increasingly common to utilise materials of this type in order to overcome the problems mentioned above and to maintain the accuracy of a firearm over time. Such stocks are often moulded to allow a large number of highly uniform accurate stocks to be provided. However, simple thermoplastic injection moulded stocks have their own disadvantages, so composite materials incorporating layered Kevlar, glass or carbon fibre reinforcement are preferable. The resulting stocks can be produced in very uniform sizes and are strong, light and highly stable.

For example, US patent 4,934,084 describes a lightweight, high strength, rifle stock. The stock comprises a reinforced polymer shell with a rigid epoxy resin filling material having voids therein to reduce the weight of the stock and the weapon overall.

One significant drawback with lighter weapons is that a user will experience a greater kick' when firing the same round at the same velocity as with a heavier weapon.

The principal of conservation of momentum means that the momentum of the round and propulsion gasses leaving the barrel of the firearm has to be reacted by the weapon itself Since momentum is the product of mass and velocity, reducing the mass of the firearm will result in an increase in the velocity at which it moves towards the user when a shot is fired. This higher velocity means that the body has less time to give and absorb the energy, which can lead not only to discomfort, but also to a loss of accuracy for the user. This is why many people choose not to use a lightweight firearm.

There are, nonetheless, many advantages associated with lightness. There will be less fatigue resulting from carrying the weapon and in particular from steadying it prior to taking a shot.

When shooting for multiple targets, a lighter firearm will also make the process of moving between targets easier and faster.

As such, there would be a desire for a firearm stock which provided the benefits of a lighter weight without the drawbacks mentioned above.

The present invention provides a firearm stock, wherein at least a part of the stock comprises a hollow outer shell filled with an energy absorbing substance.

Preferably, the stock has a hollow receiver area and handle grip area which are filled with the energy absorbing substance, for example a filled rubber compound, to create a dampening effect to the recoil reaction of the firing action. The dampening of the recoil force exerted on the operator reduces fatigue and improves accuracy during repeated firing.

The filling compound may, in particular, comprise a liquid silicone rubber mixed with glass microballoons. The compressive properties of the glass microballoons transmit shock wave energy between successive glass spheres, dissipating energy as the forces travel along the filled area of the stock. The rubber interface also enhances the energy ahsorption The remaining areas of the stock are preferably also hollow and may be filled with lightweight filler.

Preferably, the entire stock is made from a shell moulded in carbon fibre/epoxy composite, and may also comprise an integral moulded action area. The carbon fibre/epoxy composite stock provides a structure with superior rigidity and light weight, and gives strength and stiffness which helps to ensure accuracy even in differing temperatures and climatic conditions. The moulded action area ensures as close a fit as possible to transmit more effectively the recoil forces into the energy absorbing portion of the stock.

Preferably, the stock is a one piece moulding. The one piece construction method creates integrity throughout the stock to transfer and absorb forces which isolates the operator from shock waves.

A light weight barrel end can be achieved by using carbon fibre/epoxy composite, and this reduces the inertia required to move aim between targets quickly, thereby improving accuracy.

A better understanding of the present invention will be obtained from the following detailed description. The description is given by way of example only and makes reference to the accompanying drawings in which: Figure 1 is a side view of a rifle stock according to the present invention; Figure 2 is a perspective view of the rifle stock of Figure 1; and Figure 3 is a further perspective view showing a cross-section through a part of the stock.

The drawings show a stock for a rifle, but the features and principles described would also be applicable to stocks for handguns and other firearms.

The side view of Figure 1 shows three main areas of a hollow rifle stock 1. These are the barrel area 2 at the front, the butt area 4 at the rear, and a central area 6, made up of a receiver area 8 and a handle area 10, in between. A recoil plate (not shown) is located in the stock 1 between the barrel area and the receiver area 8. The stock 1 may be made from any composite, metal or plastic shell. However, carbon fibre/epoxy composite gives the best stiffness, strength and lightest weight option.

The stock I is formed by a standard moulding process. The mould tool defines the outer shape and the itmer action area 12 (see Figure 2) where the barrel action locates. This ensures as close a fit as possible between the barrel and the action area 12 to transmit more effectively the recoil forces into the energy absorbing portion of the stock. The design and manufacture of the mould tool can be to suit company specific production methods. The entire stock I is a one piece moulding for optimum results. While it would also be possible to produce the stock 1 by bonding of separate pans to make an assembly, this method may not give the required performance or be sufficiently durable over time.

The moulding of the receiver area 8 and handle area 10 of the stock I has the necessary thickness to provide rigidity and stiffhess in these key areas. Figure 3 shows a cross section of the receiver area 8 illustrating the wall thickness 14. This ensures that the trigger action area has a solid firing platform.

Within the receiver area 8 and handle area 10 the hollow stock 1 is filled with a rubber compound. The filling compound is liquid silicone rubber mixed with 5% (by weight) of glass microballoons. The glass mieroballoons are compressible. When embedded in the silicone rubber, shock wave energy created when the firearm is fired is transmifted between the glass spheres, thereby dissipating recoil energy as the forces travel along the filled area of the stock.

The ratio of rubber to glass microballoons is not limited to 5% nor is the compound limited to silicone, other suitable materials would be apparent to a skilled user. In use, the rubber compound acts as an energy absorbing substance to absorb and dampen the recoil generated when the firearm is fired.

The barrel area 2 and bull area 4 are also moulded as empty shells, and are subsequently filled with a lightweight filler or suitable density filler to achieve the required balance of the finished firearm.

The invention is not considered to be limited to the configurations and materials described above. The configuration of the structure as well as the dimensions and, to a certain extent, the material of the component parts would be dependent on a specific application.

Claims

CLAIMS1. A firearm stock, at least a part of which comprises a hollow outer shell filled with an energy absorbing substance.
2. A firearm stock according to claim 1, wherein the stock has a hollow receiver area and handle grip area which are filled with the energy absorbing substance.
3. A firearm stock according to claim 2, wherein the energy absorbing substance comprises a filled rubber compound.
4. A firearm stock according to claim 3, wherein the filled rubber compound comprises a liquid silicone rubber mixed with glass microballoons.
5. A firearm stock according to any of claims 2 to 4, wherein a barrel end of the stock is formed using carbon fibre/epoxy composite.
6. A firearm stock according to any of claims 2 to 5, wherein the remaining areas of the stock comprise a hollow shell.
7. A firearm stock according to claim 6, wherein said remaining areas are filled with lightweight filler.
8. A firearm stock according to any of the preceding claims, wherein the entire stock is made from a shell moulded in carbon fibre/epoxy composite.
9. A firearm stock according to claim 8, wherein the stock comprises an integral moulded action area.
10. A firearm stock according to any of the preceding claims, wherein the stock is a one piece moulding.
11. A firearm stock substantially as herein described with reference to the accompanying drawings.