Abstract: There is provided for a Gatling type gun, a muzzle brake torque assist device having a plurality of radial flow turbines, each centered on a respective gun barrel of the gun, each turbine for providing a respective pure torque centered on the respective barrel, and which torques translate into a summation torque centered on the longitudinal axis of the cluster of barrels without generating any lateral loads on the stationary portions of the gun.

Abstract: A firearm in the form of a submachine gun which can fire in either a semiautomatic or full automatic mode. The firearm is provided with a front sear, a front trigger and a rear sear/trigger in a construction which allows the operator to instantly change between the semi and fully automatic mode without a selector switch, even while firing. Other features include capability for ambidextrous operation, the use of two magazines each located in a separate handgrip and an improved muzzle brake configuration. In addition, an improved ejector and magazine catch assembly are provided. The firearm of the present invention employs fewer moving parts so as to require no pins or screws for the trigger, sear, bolt guide or bolt stop.

Abstract: A muzzle dampening or brake device adapted to be coaxially mounted on the muzzle end of a gun barrel. The inner diameter of the device corresponds to that of the gun barrel. The device has a pair of diametrically opposite gas exit openings. The device has a plurality of equiangularly spaced bores disposed in parallel uniformly spaced planes which place the interior of the device in communication with the exterior. The bores in each plane are angularly offset with respect to the bores of the next adjoining plane. Annular grooves are disposed on the exterior periphery of the device and are in communication with the bores to thereby permit the exiting of the smoke gases at firing and a better distribution thereof so as to minimize the blocking or lowering of visibility of the personnel servicing the gun.

Abstract: A matched expansion muzzle brake aligned with the forward end of a firearm barrel and bore including a tube having a through bore equal to and coincident with the barrel bore; outwardly diverging gas port means opening into said through bore; the gas port means including narrow throat means adjacent the opening into the through bore; and the narrow throat means having a cross-sectional area substantially equal to the cross-sectional area of the through bore.

Abstract: The barrel of a firearm is provided with side ports, on opposite sides, adjacent the muzzle. The positioning of the ports, longitudinally of the barrel, is determined according to the pressures of the explosion gases, and the acceleration of the projectile. The acceleration of the projectile occurs in response to, and during, the increase in volume of the explosion gases. This occurs only in a small portion of the length of the barrel, at the breech end, and after that position, the gases decrease in pressure. The recoil occurs after the projectile leaves the barrel and the gases leave the barrel. The side ports are adjacent the muzzle, in the region where the gases have decreased in pressure, and are dimensioned to let nearly all the gases escape by the time the projectile leaves the barrel; they are arranged diametrically opposite each other, and they cancel each other, and greatly reduce and nearly eliminate, the recoil.

Abstract: A belt-fed, gas-operated automatic weapon of a type in which the gas pressure developed in the barrel bore during firing is ported just forward of the barrel chamber to be utilized to compress a system of opposing spring sets which in turn operate the various mechanisms involved in the automatic or semi-automatic functioning of the weapon, including ammunition feeding and ejection, bolt locking and unlocking, and reciprocation. Dual power cylinders with symmetrically arranged pistons operated by the gas pressure compress all of the springs in the opposing spring sets by engagement with a sliding carriage. The forces exerted on the bolt locking mechanism by the spring sets are greatly reduced during the interval in which the locking mechanism is operated to reduce wear on the mating surfaces and to properly sequence the unlocking after discharging a round.

Abstract: A firearm including a basic action system having differential recoil, blow-back operation with moving barrel and a firing mechanism for use in conjunction with the basic action system of the invention or any other type of system operable to fire from a closed-bolt position and an open-bolt position. The basic action system utilizes a single spring which positively positions the bolt and barrel for semi-automatic, closed-bolt firing, while also providing the necessary spring and positioning action for open-bolt, differential recoil, blow-back operation. The firing mechanism of the invention provides for semi-automatic fire from the closed-bolt position, and for full automatic fire from the open bolt position, with a selector to permit selection by the gunner.