Patent ID: 7874240

Claim:
A firearm, comprising: a bolt, translatable along a longitudinal axis of the firearm; a locking lug adapted to restrict translation of the bolt along the longitudinal axis, the lug laterally shiftable with respect to the longitudinal axis, the locking lug in direct impingement fluid communication with a port in the barrel of the firearm, the locking lug adapted to be moved by fired cartridge gas from a locked position to an unlocked position; and a reinforcement portion of the firearm, fixed against translation along the longitudinal axis with respect to the bolt, the locking lug to engage the reinforcement portion in the locked position, wherein, in the locked position the lug interferes with the reinforcement portion such that the bolt is restrained from moving longitudinally along the longitudinal axis of the firearm, and in the unlocked position the bolt is free to longitudinally translate within along the longitudinal axis of the firearm.