A firearm which alloys center fire cartridges, rim fire cartridges of different sizes and types, as well as, black powder loads of different sizes to be fired from the same firearm. The aforestated is accomplished by the present invention entailing three firing pins which are selectively controlled by setting the triple mode selector located on the hammer to the desired setting. The aforementioned firearm has an internal firing mechanism lock which locks the internal firing mechanism and renders the firing mechanism inoperative. The internal firing mechanism lock is actuated by a key which can easily be carried on one's person.