Bullet for firearms

Abstract

 A bullet comprises a casing (10) having a solid head (11) and a hollow space (14) open to the rear in which a pill-shaped explosive charge (13) closes the mouth of a firing and explosion chamber (12), the latter having blind bottom and being of frusto-conical shape. Percussion of the explosive charge (13) by the firing pin causes the air of the firing and explosion chamber (12) to be adiabatically compressed, thus effecting explosion of the explosive charge (13) and firing of the bullet.

Description

[0001] The present invention relates to a projectile, particularly a bullet for firearms, such as pistols, guns, etc. As it is known, a bullet normally comprises a metal casing of tapering shape and at least partially hollow, within which the explosive propelling charge is located. The latter has associated thereto a priming cap, serving to activate the propelling charge due to a percussion action of a mechanical member of the firearm (i.e. the percussion pin). Some types of bullet further comprise a cartridge case which remains in the firearm and must be ejected after each shot, thus limiting the firing rate and, consequently, the firing power (in the quantitative meaning) of the firearm. Moreover, the necessity of a priming cap and of the cartridge case causes a relevant increase, not only with respect to the number of component parts, of the production costs of the bullets.

[0002] Another not negligible problem is that, in the case of defective operation of the priming cap,the whole bullet must be discarded, since the substitution of the priming cap can not be taken into consideration for economical reasons. Lastly, it should not be forgotten that the presence of the priming cap, which necessarily must be highly sensitive, involves remarkable cautions in the handling and storage of the projectiles.

[0003] It has been now found that these problems and drawbacks are essentially done away with a bullet of the type comprising a metal casing of tapered shape, said casing being partially hollow, characterized in that in the wall of said hollow space of said casing, perpendicularly to the longitudinal axis of the casing, a firing and explosion chamber is formed, the chamber being of frusto-conical shape and having blind bottom, the open end of the chamber being covered by a charge of tamped explosive material.

[0004] The specific features and advantages of the present invention will appear more clearly from the following detailed description of a preferred embodiment, having illustrative but non limiting purpose, with reference to the enclosed drawing showing a longitudinal cross section view of the bullet. With reference to the drawing, the reference 10 does generally indicate the casing of the bullet, comprising a solid head 11 and a rear hollow space 14.

[0005] At the rear part of the casing 10, a shoulder 15 of greater diameter is provided, which is connected to the head 11 of the bullet by an annular frusto-conical part 16 having an inclination of 40-45*.

[0006] The diameter of the shoulder 15 corresponds to the true diameter of the barrel of the firearm, whereas the diameter of the casing 10 corresponds to the diametral spacing between the riflings protruding from the inner surface of the said barrel.

[0007] Thus the bullet can not be accidentally forwardly displaced in the barrel, during the percussion, (with the consequent safety of firing) and the shoulder 15, on firing the bullet, is drawn to the size of the internal riflings of the barrel. In the rear wall of the hollow space 14, which defines the solid head 11, the firing and explosion chamber 12, of frusto-conical shape and having blind bottom, is provided.

[0008] The open end of the chamber 12 is closed by a pill 13 of explosion material particularly nitrocellulose,preferably shaped with a recess corresponding to said explosion chamber.

[0009] As regards the operation of the bullet according to the invention, it is to be pointed out that it is based on a principle, discovered in recent years with respect to explosive caseless pills as used in the explosive actuated tools for driving pointed members, nails and the like.

[0010] This principle is based on the fact that, by means of a blind explosion chamber of frusto-conical shape and of proper size
the adiabatic compression of the air present in the chamber, as caused by the penetration of the pill or of a part thereof under the action of the percussion pin, brings the same air, in a practically instantaneous way, to the temperature and pressure conditions necessary and sufficient for the firing and the explosion of the explosive material forming said pill.

[0011] It has been particularly found that the compression ratio - of the air present in the said chamber must be of about 1 to 20.

[0012] From the preceding considerations, the operation of the bullet of the invention is clear, since the action of the percussion pin on the explosive charge 13 causes the air in the chamber 12 to be adiabatically compressed and thus the firing of the bullet, without case remaining in the barrel.

[0013] In the case in which a better protection of the explosive charge 13 is desired, it may be protected by a thin coating of plastics or of a paint, or by means of a small disk of paper or of paperboard.

[0014] Of course the invention has been generally described, but the size of the casing and the power of the explosive charge must be selected according to the type and caliber of the firearm, etc.

[0015] Moreover mechanically and/or ballistically equivalent changes are possible and foreseable within the scope of the invention.

Claims

1. Bullet for firearms of the type comprising a metal casing (10) of tapered shape, said casing (10) being partially hollow, characterized in that in the wall of said hollow space (14) delimiting the solid head (11) of the casing a firing and explosion chamber (12) of frusto-conical shape and with blind bottom is formed, the open end of said chamber (12) being closed by a tapped charge (13) of explosive material.

2. Bullet according to the claim 1, characterized in that said tapped charge (13) is outwardly protected by a protective coating of plastic material, paint, paper and the like.

3. Bullet according to the claim 1, characterized in that said tapped charge (13) is shaped with a recess corresponding to said firing and explosion chamber (12).

4. Bullet according to claim 1, characterized in that said casing (10) is shaped, in the rear part, with a shoulder (15) of a diameter corresponding to the internal diameter of the barrel of the firearm.

Drawing