Breech block control for firearm for projectiles

Abstract

The invention concerns a firearm for receiving and firing a projectile. The firearm includes an integral casing having a barrel and a breech block receiving area to the rear of the barrel. A breech block is guided through the breech block receiving area by separated guide pins which project from the breech block into respective longitudinal track sections in the barrel. The guide pins are axially separated at opposite ends of the breech block and are circumferentially separated. The longitudinal track sections meet circumferential track sections. The guide pins in the circumferential track sections permit the breech block to be rotated. The breech block has a forward closed barrel position and a rearward open loading position. A breech mount around the breech block has a cam slot that extends longitudinally and into which a cam follower pin from the breech block projects. The breech mount is drawn forward by a spring and driven rearwardly by the gas pressure from detonation of a projectile leaving the barrel. To load a projectile in the barrel, the forwardly moving breech mount moves the breech block forward along the longitudinal track sections to the forward breech closed position and then rotates the closed breech block to the locked position in the circumferential track sections.