Abstract: An auto-loading firearm has a frame defining a bolt passage, a bolt operable to reciprocate between a battery position and a retracted position, a barrel defining a gas aperture, an energy transmission facility having a first end communicating with the gas aperture and an opposed second end, the bolt having a bolt body and a bolt key movable with respect to the bolt body between a forward position and a rearward position, the bolt key operably engaging the second end of the energy transmission facility when the bolt is in the battery position, the bolt including a latch element operably engaged to the bolt key having a locked position to prevent reciprocation of the bolt, and an unlocked position in which reciprocation of the bolt is enabled, and the latch element being responsive to rearward motion of the bolt key to move from the locked position to the unlocked position.

Abstract: An auto-loading firearm has a frame defining a bolt passage, a bolt operable to reciprocate between a battery position and a retracted position, a barrel defining a gas aperture, an energy transmission facility having a first end communicating with the gas aperture and an opposed second end, the bolt having a bolt body and a bolt key movable with respect to the bolt body between a forward position and a rearward position, the bolt key operably engaging the second end of the energy transmission facility when the bolt is in the battery position, the bolt including a latch element operably engaged to the bolt key having a locked position to prevent reciprocation of the bolt, and an unlocked position in which reciprocation of the bolt is enabled, and the latch element being responsive to rearward motion of the bolt key to move from the locked position to the unlocked position.