Abstract: A machinegun pistol is described, which can be reliably switched between semi and full automatic modes by an operator holding the gun in a natural two-hand grip. The gun includes a bolt (20, FIG. 1) and a firing pin device 22 that each slide longitudinally, a trigger assembly with a primary sear (28) that is depressed by the trigger for semiautomatic operation, and an auto control member (34) that can be depressed to switch to full automatic operation. When the control member is depressed, it connects a secondary sear (36) with the primary sear. The bolt carries a cam (40) that can depress the secondary sear (36) when the bolt moves forward, to thereby repeatedly depress the primary sear (28) when the two sears are connected during automatic operation. The control member (34) is operated by depressing it into the frame, to avoid errors in the heat of battle. The depressable control member (34, FIG.