GB2136935A

GB2136935A - Firearms

Info

Publication number: GB2136935A
Application number: GB08407805A
Authority: GB
Inventors: John Harness
Original assignee: Hilton Gun Co Ltd
Current assignee: Hilton Gun Co Ltd
Priority date: 1983-03-26
Filing date: 1984-03-26
Publication date: 1984-09-26
Also published as: GB2136935B; GB8407805D0

Abstract

A firearm, especially of the type used to disperse rioters, comprises a gun body (10) with a breech block (16) secured by a catch (20) and having a snap fit arrangement (34) for releasably mounting selective barrels, for example barrel (32). The barrels are interchangeable and can be of different lengths to be suitable for firing different types of ammunition. One or more of the barrels is also adapted to receive a barrel insert which enables the riot-gun to fire ammunition of different calibres. The riot-gun is therefore adaptable to fire ammunition such as large- or small-calibre flare rounds, baton rounds, gas cartridges and live ammunition. <IMAGE>

Description

SPECIFICATION Firearms The invention relates to firearms, especially, though not exclusively, firearms for use by security forces for dispersing rioters and the like.

It is known to provide 'riot-gun' firearms to fire one of a number of different typss of ammunition such as large- or small-calibre flare rounds, batonrounds, gas cartridges and live ammunition such as shotgun rounds.

Unfortunately this has required the utilisation of a large number of firearms, and it is impracticable for a user to have to carry several firearms to suit different calibres or types of ammunition.

The invention provides a firearm adapted to selectively fire ammunition of two or more different calibres, the firearm comprising a gun body incorporating a firing mechanism, at least two interchangeable barrels, the gun-body having means for selectively receiving one of said at least two interchangeable barrels in a releasably securable manner, and means for releasably securing, in at least one of said barrels, a barrelinsert permitting the use of ammunition of a smaller calibre than the barrel in which the barrelinsert can be received.

Preferably the gun body comprises a main part, which incorporates a firing mechanism, and a breach part which is pivotally mounted on the main part. Alternatively the breech part is releasably mounted on the main part.

Preferably also the barrel receiving means of the gun body comprises a screw threaded arrangement arranged to co-operate with a screw threaded arrangement of each of the barrels.

Alternatively the barrel receiving means of the gun body comprises a snap fit arrangement adapted to co-operate with parts of each of the barrels.

The insert receiving means may comprise a recess in said at least one barrel for receiving a flanged end of the insert, whereby the latter can be clamped between the barrel and the main part of the gun body.

In another arrangement the insert receiving means may comprise a recess in the breech part for receiving a flanged end of an insert arrangement, whereby the latter can be clamped between the breech part and the main part of the gun body.

The insert arrangement may comprise a member within which the insert is mounted and which is adapted to space the insert from the barrel, the flanged end being provided in the spacing member.

Desirably means are provided on the gun body for ejecting spent cartridge cases, the ejecting means being adapted to co-operate either directly with the cases or indirectly with the cases by means of auxiliary ejecting means associated with the insert.

Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which: Fig. 1 is a schematic side elevational view of a firearm according to the invention, fitted with a large-calibre barrel, certain parts being shown in cross-section; Figs. 2a and 2b are schematic side elevational views of a front part of the firearm similar to that shown in Fig. 1, having fitted thereto a smallcalibre barrel-insert inside the large-calible barrel; Fig. 3 is a cross-sectional view of a part of the firearm of Fig. 1, having fitted thereto a short large-calibre barrel with a small-àlibre barrel insert therein; and Fig. 4 is a cross-sectional view of a part of the firearm shown in Fig. 1, showing an alternative barrel mounting.

Fig. 1 shows a firearm having a gun body 10 having a socket at a rear part for receiving a stock 12 and having a pistol grip 14. A breech block 16 is mounted on the gun-body 10 by means of a pivot 18, the breech block being secured to the gun-body for firing by a catch 20.

The gun-body 10 has a firing mechanism (only part of which is shown) including a firing pin 22, a part 24 of which is provided with an aperture 26.

The latter can receive a locking pin 28 which is depressed against the urging of a spring 30, unless the catch 20 is properly engaged with the breech block 1 6. The firearm is thus prevented from firing unless the breech block is in proper engagement with the gun body 1 0. The breech block 1 6 receives the breech end of a barrel 32 in a sliding fit within a socket, the barrel being locked in place by a series of ball catches 34. These comprise a series of eight circumferentiallyspaced ball bearings 36 which, in the locked position, have lower portions which can protrude into a circumferential groove provided on the outside of the barrel socket. The ball bearings 36 are held in this position by a sleeve 38 urged into a locked position by a spring 39.When slid aside against the spring 39 the sleeve 38 allows the ball bearings 36 to retract from the socket allowing the barrel 32 to be withdrawn.

The breech block 1 6 also incorporates a cartridge ejector mechanism comprising an ejector slide 40 having an abutment 40a which, when the breech is pivoted open, abuts a stop 42, on the gun body 10. The latter, as the breech is opened more, pushes the ejector slide 40 rearwardly relative to the breech block so that an abutment 40b ejects the rim of a cartridge 46. The barrel 32 shown in Fig. 1 is a 38 mm-calibre long barrel suitable for firing a baton-round (for example of rubber or plastics) or a gas-round. A short barrel 70 as shown in Fig. 3 and as described in more detail hereinafter can be fitted instead of the long barrel so that the weapon can be used as a pistol. The short barrel can be used for firing 38 mm-calibre flare rounds, or gas or baton-rounds, where accuracy is not required, or in an emergency.

Figs. 2a and 2b show a firearm similar in most respects to that shown in Fig. 1 (and similar reference numerals have been used for corresponding parts), except that a barrel 50 is screw threaded into the breech block 16, and the firearm is shown with a small (12 gauge) calibre barrel insert 58 within the 38 mm-calibre barrel 50. Fig. 2a shows the rear part of the barrel 50, and Fig. 2b the front part.

The large calibre barrel 50 is attached to the breech block 1 6 by means of an external screw threaded section 52 and is prevented from unscrewing by means of a locking screw 54 which is tightened on to an outer surface of the barrel socket. A barrel-insert assembly is received within the barrel 50 and comprises a rear spacing block 56 into which is threadingly engaged the barrel insert 58. A forward spacing block 60 (see Fig. 2b) spaces the small-calibre barrel insert 58 within the barrel 50 at a front end of the latter. The cartridge ejector slide 40 instead of acting on the rim of a cartridge, acts on an abutment of a secondary ejector 62 which is part of the spacing block 56 and which acts on the rim of a cartridge in the small-calibre barrel insert 58 to eject the cartridge case.

Fig. 3 shows part of the breech block 1 6 of the firearm of Fig. 1 incorporating the short barrel 70 as an alternative to the long 38 mm-calibre barrel 32. There is also shown a small 1 "-calibre barrel insert 72 (for firing small baton or flare rounds) retained in the barrel 70 by means of a flange 74 corresponding to the rim of a large-calibre cartridge. A secondary ejector 76 is provided which is operated by an ejector slide 78 of the large-diameter barrel 70 in a manner the same as that described in relation to the firearm shown in Fig. 2a.

Fig. 4 shows an alternative type of screw thread arrangement for securing a barrel 80 to a breech block 82, by means of an 'acme' thread 84.

It is to be understood that various modifications may be made without departing from the invention. For example, any convenient fixing of a barrel in the breech block may be employed, the examples shown being the screw-thread and snap-fit arrangements. A permanent barrel may be provided on a breech block within which barrel inserts of other calibres may be received by any suitable means in addition to those described, the breech block being rapidly interchangeable with another breech block having a permanent or detachable barrel. The breech block may be secured for example by a releasable pivot pin.

The firearm may be made from any suitable material such as alloy, pure metal, and where appropriate, plastics. Where a long barrel is fitted, an additional hand-grip may be fitted about half way along the barrel. The hand-grip(s) and/or stock may be provided with rings to accommodate a sling.

The barrel or any of the barrels may be rifled where appropriate. Each barrel or barrel insert (when fitted) may be used to fire any appropriate ammunition. For example the 12-gauge barrel may be used to fire a gas, buckshot, or slug-round (for example to kill escaped dangerous animals).

Claims

1. A firearm adapted to selectively fire ammunition of two or more different calibres, the firearm comprising a gun body incorporating a firearm mechanism, at least two interchangeable barrels, the gun body having means for selectively receiving one of said at least two interchangeable barrels in a releasably securable manner, and means for releasably securing, in at least one of said barrels, a barrel insert permitting the use of ammunition of a smaller calibre than the barrel in which the barrel insert can be received.

2. A firearm according to claim 1 , wherein the gun body comprises a main part, which incorporates a firing mechanism, and a breech part which is pivotally mounted on the main part.

3. A firearm according to claim 1, wherein the gun body comprises a main part, which incorporates a firing mechanism, and a breech part which is releasably mounted on the main part.

4. A firearm according to any of claims 1 to 3, wherein the barrel receiving means of the gun body comprises a screw threaded arrangement arranged to co-operate with a screw threaded arrangement of each of the barrels.

5. A firearm according to claim 4, wherein releasable locking means are provided to lock the selected barrel in position in the gun body.

6. A firearm according to any of claims 1 to 3, wherein the barrel receiving means of the gun body comprises a snap fit arrangement adapted to co-operate with parts of each of the barrels.

7. A firearm according to claim 6, wherein the snap fit arrangement comprises a plurality of ball catches engageable in a circumferential groove in each barrel, and a sleeve movably mounted on the gun body to move the ball catches into a locking position.

8. A firearm according to any of the preceding claims, wherein the insert receiving means comprises a recess in said at least one barrel for receiving a flanged end of the insert, whereby the latter can be clamped between the barrel and the main part of the gun body.

9. A firearm according to claims 2 or 3, or any of claims 4 to 7 when dependent on claims 2 or 3, wherein the insert receiving means comprises a recess in the breech part for receiving a flanged end of an insert arrangement, whereby the latter can be clamped between the breech part and the main part of the gun body.

10. A firearm according to claim 9, wherein the insert arrangement comprises a member within which the insert is mounted and which is adapted to space the insert from the barrel, the flanged end being provided on the spacing member.

11. A firearm according to claim 10, wherein the insert is releasably mounted in the spacing member.

1 2. A firearm according to claim 11, wherein the insert is threadably secured in the spacing member.

1 3. A firearm according to any of the preceding claims, wherein means are provided on the gun body for ejecting spent cartridge cases, the ejecting means being adapted to co-operate either directly with the cases or indirectly with the cases by means of auxiliary ejecting means associated with the insert.

14. A firearm according to any of the preceding claims, wherein at least one of the barrels is provided with a hand grip.

1 5. A firearm according to any of the preceding claims, wherein at least one of the barrels is rifled.

1 6. A firearm according to any of the preceding claims, wherein said at least one insert is rifled.

17. A firearm according to any of the preceding claims, wherein a piurality of barrel inserts are provided and each is receivabie in at least one of the barrels.

1 8. A firearm according to any of the preceding claims, wherein means are provided on the gun body for receiving a stock, whereby the firearm can be shoulder-held.

1 9. A firearm substantially as hereinbefore described with reference to the accompanying drawings.

20. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.