Single shot pistols have been around from the very beginning. It has many configurations possible for igniting a cartridge, such a hammer (similar to a revolver) or firing pin striker (like a bolt action rifle). You can find single shot pistols in almost any cartridge made (both pistol and rifle calibers). Barrels from 2 inches long to 15 inches long are common. Today these pistols are used mostly for taking anything from small to large game animal.