Two semi-auto guns were categorized as the single-action pistols while the other three were double-action pistols. All of them are operated by the previous shot fired, the spent case ejected, and a fresh cartridge from their magazines loaded into the chamber to complete the cycle. This continues until their magazines are empty. The trigger of the single-action a semiauto can be pulled after its hammer is cocked whereas the one of the double-action pistol can be pulled as the hammer is in either cocked or lowered position.