Semi-rigid lock for small firearm breech block - has sliding wedge in breech block rear locked by roller

摘要

The breech mechanism of a small firearm has an integral unit consisting of a handle with barrel and cartridge chamber. The breech block is held firmly until the bullet has left barrel for full utilisation of gas pressure. The breech block is released immediately after the bullet has left the muzzle. The breech block locking roller is held in a transverse horizontal groove and is in contact with an inclined plane of the locking wedge sliding within the breech block. The longitudinal movement caused by the recoil jams this arrangement. The acceleration in longitudinal direction opposite that of the firing direction ensures the opposite movement for the locking wedge and releases the locking roller from its groove so that the breech block is released. The breech block moves backwards and the cartridge case can be ejected.