Rotating bolt

Rotating bolt is a method of locking found most often in gas operated firearms in which the bolt, upon contact with the breech rotates and locks into place, being held in place by lugs attached to the breech or barrel extension.

Upon closing, the bolt passes through the slots cut in the front of the barrel extension, and then rotates; at this point it is locked in place until the action is cycled, either manually by the operator, or mechanically by the gas created by discharging the rifle pushing on the operating rod or bolt carrier, which then rotates the bolt to the right and unlocks it from the breech so that it can be withdrawn in order to extract and eject the spent casing, and chamber a new round.