GB461346A - Improvements in automatic guns - Google Patents

Abstract

461,346. Automatic guns. WILLIAMS, D. M. June 13, 1935, No. 17038. [Classes 92 (ii) and 119] Relates to automatic guns having bolt-mechanism designed to operate with cartridges of normal calibre and explosive intensity and in which automatic operation is effected by a movable cartridge chamber or actuator in close proximity to the rear of the barrel at the time of firing. According to the invention, the movable chamber is adapted to receive explosion gases from a ball cartridge of lower than normal intensity and has a gas contact area so designed that the subnormal ammunition effects normal operation of the gun. The actuator and barrel are arranged to prevent the rearward escape of the gases at least until after the actuator has moved rearward a predetermined distance. The invention is applicable to machine guns, automatic pistols and automatic rifles and is particularly applicable to adapting such weapons for operation with sub-calibre ammunition. Fig. 4 shows a Browning machine gun adapted for operation by sub-calibre ammunition 58 which is fed into a chamber member or actuator 52 slidable over the rear end of a fixed sub-calibre barrel 59. The actuator is connected to the usual barrel extension member 32 which serves to operate the breech mechanism. After firing, the bullet 58b leaves the cartridge case as shown, and the gases acting on the surface 56 force the actuator rearwards, escape of gas being prevented by the packing ring 67 until longitudinal grooves 57 are uncovered, when the gases escape into a chamber .66 open to the atmosphere. The rear end of the barrel is flared at 61 to equalize the pressure of gas round the projecting end 58a. of the cartridge case. Fig. 6 shows the position of the parts with the breech open. The cartridge-feed mechanism is that described in Specification 461,741. Fig. 15 shows a movable chamber or actuator 86 applied to a Colt automatic pistol of the kind described in U.S.A. Specifications 984,519 and 1,070,582. The usual large calibre movable barrel is replaced by a fixed sub-calibre barrel 82 and the movement of the actuator is limited by a projection 88 engaging a stop surface 84. Sub-calibre ammunition is fed by a magazine 100, the gun being otherwise of standard weight and construction, except for a modified ejector which is necessary for the shorter ammunition. Fig. 18 shows the application to an automatic rifle in which the actuator 110 has a loose screw-threaded engagement with the barrel 117 the movement of the actuator being limited by the tolerance of the threads.