GB2106222A

GB2106222A - Improvements in and relating to practice ammunition

Info

Publication number: GB2106222A
Application number: GB08223808A
Authority: GB
Inventors: Lars Ringdal
Original assignee: Bakelittfabrikken AS
Current assignee: Bakelittfabrikken AS
Priority date: 1981-08-18
Filing date: 1982-08-18
Publication date: 1983-04-07
Also published as: FR2511765B3; NO148725B; DE3229885A1; GB2106222B; NO148725C; CA1204961A; NO812786L; FR2511765A1

Abstract

Practice ammunition of plastics, wherein the assembly of the cartridge casing O and the projectile portion D is reinforced by inserting a metallic body A having a bore B for receiving a tracer light charge. The metallic body A is provided with gripping teeth I on the external surface, directed towards the centre of the metal insert, which is positioned approximately half in the projectile and half in the forward extension of the casing. <IMAGE>

Description

SPECIFICATION Improvements in and relating to practice ammunition The invention relates to practice ammunition comprising a casing and a projectile made of plastics, wherein the front end of the casing is closed by a tearable wall having a cylindrical hollow extension for the attachment of the projectile.

Norwegian patent 1 13 440 describes such a closure of the front end of a casing, with the attachment of the projectile by external threads on the extension of the casing and corresponding internal threads in a cavity of the projectile.

However, experience has shown that this kind of attachment causes problems, especially with small calibre ammunition. The present invention relates to a completely novel system for attaching the projectile to the ammunition casing, wherein the drawbacks of previously proposed attachment systems may be avoided. An attachment means is used which combines several substantial functions. Thus, the invention is characterised in that a metallic body having gripping means on the external surfaces of both ends and directed to the centre of the body is inserted for approximately one half of its length into a cavity in the extension of the ammunition casing and the other half is inserted into one part of an offset cavity in a projectile portion which has been pushed down over the extension.The metallic body used also offers the advantage of providing a projectile which is heavier and thus has directional stability over a longer distance. It is furthermore possible to provide a cavity in the metallic body for insertion of a tracer light charge as well as to form partial bores or shortened bores in order to give exactly the same weight to the projectiles with and without the tracer charge.

It is known in shooting with plastics projectiles with a metal cup for a tracer charge mounted inside, that the metal cup will increase the weight of the projectile and it is common in training shooting to use ammunition mounted in belts or bands or cassettes and every fifth round then is ordinarily a tracer round. The difference in weight then has the effect that the tracer rounds, having a heavier projectile, will have a different trajectory from the other projectiles and the hits on the target will be very poorly grouped. This drawback may be avoided by means of the present invention, because there need be no variation in the weight of the projectile according to whether it contains a tracer charge or not, because drilling or smaller drilling out of the metallic part when the ammunition is produced without tracer charges does not occur.

According to the present invention one end of the metallic insert provided with gripping means is arranged in the extension of the ammunition casing. The other end is inserted into a cavity in the projectile part when this is pushed down onto the extension. With a close fit the gripping means then will retain the two parts with good attachment to each other during firing. It is important that the external side of the extension of the casing and the corresponding internal side of the projectile part have very smooth and excellently fitted surfaces.During firing and tearing of the extension of the ammunition casing, a very high gas pressure will be present inside the ammunition and it is important that the gases are not allowed to penetrate between the external wall of the extension and the internal wall of the projectile portion, because in that case there is danger of explosion and tearing off of parts of the projectile.

In another embodiment according to the invention the metallic part has at one end an approximately cylindrical expanded portion which may be fitted into a corresponding chamber in the extension of the ammunition casing and which then will be well locked when the portions of the projectile are assembled with a close fit. Another important detail of the invention with the use of certain types of plastics comprises the fact that the bottom of the extension of the casing may be drawn somewhat forwards so that, when the projectile has been assembled, the end surfaces will be in alignment with or inside of the rear end of the projectile. On firing, the projectile will have a rapid rotational movement on leaving the muzzle of the weapon.In order to prevent the metallic body from having, owing to its greater weight, a different rotational movement from the surrounding projectile part of plastics, the metallic body in accordance with the invention has been provided with gripping means which are in engagement with the plastic material in such a way that plastics and metal will have the same rotational speed.

Various forms of ammunition constructed in accordance with the invention will now be described by way of example only with reference to the accompanying drawings, in which: Fig. 1 shows two forms of the metallic body; Fig. 2 shows one form of projectile and ammunition casing assembled without the metallic body; Fig. 3 shows one form of the metallic body inserted into one form of the ammunition; and Fig. 4 shows the other form of the body inserted into another form of the ammunition.

Fig. 1 shows two forms of metallic body A having a cavity B for the reception of a tracking light charge (not shown) and wherein the body A in the one case has been provided with external toothing at both ends and in the other case has a cylindrical expanded portion C at one end. Fig. 2 shows a projectile D and an ammunition casing 0 in assembled condition, but without a metallic body A. In the projectile portion has been provided a cavity E for reception of approximately one half of the body A and in an extension of the ammunition casing has been provided a cavity G for positioning of the other half of the body. A channel H enables the fired gases in the ammunition casing to reach the body A. Fig. 3 shows the body positioned with external toothing I on the body engaging the internal walls of the cavities E and G. Fig. 4 shows a body of the type shown at the bottom of Fig. 1 arranged in the projectile and casing of the ammunition with its expanded part C in the extension of the casing.

Fig. 4 shows an end wall K of the ammunition casing extension being displaced further forwards so that it will be positioned inside the hindmost part L of the projectile surrounding projectile portion D from having different rotational speeds, the body A has been provided with a groove at one end of the metal part which has been pressed into the projectile. In order to obtain a larger cavity G the extension of the ammunition casing may be provided with one or more grooves N.

Claims

1. Practice ammunition comprising a casing and a projectile made from a plastics material, wherein the front end of the casing is closed by a tearable wall having a cylindrical hollow extension; and a metallic body, provided with gripping means on the external surface of both end portions and directed towards the centre of the body, has been inserted approximately one half into a cavity in the extension of the casing and the second half into one portion of an offset cavity in the projectile which is on the extension.

2. Ammunition according to claim 1, wherein the metallic body at one end is provided with a cavity for the reception of a tracer charge.

3. Ammunition according to claim 1 or claim 2, wherein the gripping means on the metallic body extends in opposite directions and at one end consists of an approximately cylindrical expanded portion which is received in a corresponding expansion in the extension of the end portion of the casing.

4. Ammunition according to any one of claims 1 to 3, wherein the extension of the ammunition casing has smooth external surfaces having a close fit with the intemal wall of the rear part of the offset cavity in the projectile portion.

5. Ammunition according to any one of claims 1 to 4, wherein the tearable wall of the front end of the ammunition casing has been drawn forwardly so that after firing the bottom of the wall will be aligned with or inside the rear part of the projectile.

6. Ammunition according to any one of claims 1 to 5, wherein the metallic body is also provided with gripping means preventing lateral rotation in the plastics projectile portion.

7. Practice ammunition substantially as hereinbefore described with reference to, and as shown in, Fig. 2, or Fig. 3, or Fig. 4, of the accompanying drawings.