Abstract: A semi-automatic firearm apparatus has a recoil rod having a recoil spring associated with it, wherein the recoil rod faces in a first direction and projects outwardly from the semi-automatic firearm apparatus and a hold back member connected to the semi-automatic firearm apparatus and movable between a first position where it does not block the movement of the recoil rod and a second position where it does block the movement of the recoil rod.

Abstract: A hammer is adapted to receive a removable firing pin and includes an axial bore for receiving the firing pin and a transverse bore for receiving pins to secure the firing pin within the axial bore. The transverse bore includes a slave pin section for receiving a slave pin configured to mate with an annular groove or machined notch in the firing pin and a screw pin section for receiving a screw pin to secure the slave pin and the firing pin.

Abstract: A revolver includes a frame; a hammer rotatably coupled to the frame; a trigger mounted on the frame and movably coupled to the hammer; a cylinder rotatably mounted on the frame and having more than six chambers, each of the chambers adapted to receive a cartridge, wherein the cylinder is rotatable into discrete firing positions; and a pawl connected to the hammer for moving the cylinder between the discrete firing positions.

Abstract: The present invention is directed to a revolver, where headspace is achieved differently and separately from the barrel, where [a cartridge is placed in the cylinder] and where that headspace is a function of caliber and varies per caliber/cylinder. The system of the present invention links a unique barrel and cylinder relationship so that each may be exchanged with the other set on the same frame. A tension ring is used to threadedly engage the interchangeable barrel relative to the interchangeable cylinder and revolver frame such that the predetermined headspace is preserved. And all being fit to differing headspace points within the single revolver frame. Each could be numbered so that confusion of which cylinder with which barrel be reduced.