Abstract: A semiautomatic pistol has a frame which supports a barrel and breech-slide for chambering a cartridge in the breech end of the barrel and extracting a spent cartridge. The breech-slide carries an inertia type firing pin which is displaced to fire a chambered cartridge by a hammer pivotally mounted upon the frame. A trigger bar, mounted upon a trigger displaces a sear to release the hammer when the trigger is pulled. A breech-slide operated disconnect causes pivoting of the trigger bar as the breech-slide recoils to allow the sear to snap back to a position in which it can engage the searing surface of the hammer when the breech-slide moves forwardly.A firing pin lock is biased to a position where the pin is free to travel under the impetus of a falling hammer. The upper surface of a pivotally mounted shell ejector normally engages the firing pin lock to maintain it in a position where the firing pin is locked.

Abstract: A recoil assembly for an automatic firearm, including a reciprocating bolt and carrier assembly, has a hydraulic buffer to provide a reduced rate of fire and prevent wide fluctuation in the round to round rate of fire. The buffer includes a piston which pushes hydraulic fluid through an orifice when depressed by the bolt and carrier assembly at the end of its recoil stroke. When the bolt and carrier assembly begins to displace the piston, hydraulic retardation is immediate. A spring loaded sliding seal pushes the hydraulic fluid through the orifice during the return stroke which returns the piston to its original extended position. The buffer also prevents carrier bounce and promotes a mild recoil shock.