Made after World War Two until 1957, the Ballester Campeon was a .22 rimfire competition pistol built on the frame of the Argentine Ballester-Molina .45 ACP service pistol. Two versions were made, a standard 5 inch (127mm) barrel with normal sights and the longer 7.5 inch (190mm) Campeon model with larger adjustable sights. Both use the floating chamber system to function, allowing them to run reliably regardless of barrel length. A few thousand of the standard .22s were made, and only a few hundred of the Campeons.