 The bolt is moved into and out of the locked position via a cam pin that engaged a helical slot in the bolt carrier, which rides on two metal guide rods (each with its own return spring) instead of contacting the receiver walls, providing additional clearance for foreign matter entering the receiver.Unlike the AR-15, the cocking handle fits directly into a recess in the bolt carrier and reciprocates with it during firing, allowing the firer to force the breech closed or open if necessary.The cocking handle slot has a spring-loaded cover that can be closed by the user to prevent debris entering the receiver, and it will open automatically as the bolt carrier moves rearwards after the first shot.