`The operation of the firearm is as follows:
To operate as a hand-operated arm, the muzzle piece is screwed in to seat against the muzzle of the barrel, thus cutting off' entry be formed to receive the of gas to the cylinder and piston. The bolt may then be retracted manually through the bolt handle.
To operate semi-automatically, the muzzle piece is screwed out away from the muzzle of the barrel to allow a desired amount of gas to enter the cylinder and act on the piston.
A clip containing cartridges is inserted in the magazine, being held in place therein by the clip latch. This action depresses the follower, rocks the connecting rod catch to free the clip latch and connecting rod, and also moves the indicator to register full magazine. Insertion of the clip releases the bolt which moves forward, inserting a cartridge in the chamber and leaving the arm in a position to be fired.
Upon firing the bolt remains locked until the bullet has passed from the barrel, allowing the gases of explosion to enter the cylinder and force the piston and connecting rod rearwardly. Rearward movement of the connecting rod cams the bolt to unlocked position and at the same time cams the firing pin to safe position, then carries the bolt rearwardly allowing the extractor to extract the empty shell which is then ejected by the ejector.
Movement of the piston, connecting rod and bolt rearwardly, compresses the spring housed in the connecting rod, thereby assuring sufficient pressure on the follower rod to actuate the follower to force a cartridge from the clip into the path of the bolt on its forward movement which movement is caused by the expansion of the aforesaid spring.
The combination with a gun, including a magazine, of a clip for insertion in the magazine, means for latching the clip in place, a follower, means for actuating the follower to force cartridges from the clip, means actuated by actuation of the follower' when the clip is empty to unlatch the clip, and a resilient element secured to the bottom of the magazine for automatically expelling the clip when unlatched.