653,648. Automatic guns. TRIGGS, W. W. (Aktiebolaget Bofors). March 5, 1948, No. 6887. [Class 92 (ii)] Relates to short recoil automatic guns of the kind in which latches on the breech block are actuated during recoil through a release member pivoted to the barrel, the breech being opened by direct action of the gun gases on the cartridge case. According to the invention, the release member is pivoted below the barrel and during recoil strikes a fixed abutment to entrain a sliding member having cam surfaces to release the latches and impart an initial rearward movement to the breech block which movement is completed by the action of the gun gases. In the form shown, the breech block 12 is unlocked, on recoil of the barrel 1 after firing, by a lever 8 turning on a pivot 9 on the barrel extension 7, the arm 52 of the lever engaging a fixed stop 53 and the forked arm 81 engaging a striker plate 37 to move it rearward with striker sleeve 16 against the action of a spring 39, thereby releasing, through inclines 48, the pivoted latches 46 on the breech block from engagement with abutments 51 on the barrel extension. Thereafter, the gun gases acting through the cartridge case exert a blow-back action on the breech block to move it to open position against the action of a return spring 26. On closing movement, the forward inclines 50 on the striker sleeve 16 move the latches into engagement with the abutments 51, and the striker plate 37 moves forward to fire the gun by firing pin 35. Specification 574,352 is referred to.