Abstract: A breech bolt lock-up device for a firearm absorbs linear inertial forces and utilizes the absorbed inertial force to linearly cycle the firearm. The lock-up device includes an inner lock sleeve and an outer lock sleeve. A locking device will releasably lock the inner lock sleeve with the outer lock sleeve. A cam member is axially aligned with the inner lock sleeve and the outer lock sleeve. The cam member is engagable with the locking device for releasing engagement between the inner lock sleeve and the outer lock sleeve. The cam member linearly reciprocates relative to the gun barrel. A cam spring is provided for storing linear inertia energy when the cam member moves forward. A recoil spring will store linear inertia energy when the cam member moves rearwardly.

Abstract: A lock-up device for a firearm which utilizes a ball and cam arrangement to interlock two members. The interlocked members include ball engagement surfaces which are curved so that a substantial portion of the ball surface is in contact with the engagement surfaces. The lock-up device disposed in a firearm absorbs recoil forces and utilizes the absorbed recoil force to cycle the firearm.

Abstract: A lock-up device for a firearm which utilizes a ball and cam arrangement to interlock two members. The interlocked members include ball engagement surfaces which are curved so that a substantial portion of the ball surface is in contact with the engagement surfaces. The lock-up device disposed in a firearm absorbs inertia forces and utilizes the absorbed inertia force to cycle the firearm.