Ruger super single six serial 563xxx The box says Super "SINGLE" Six below that .22WMR Caliber Revolver. Also catalog number SC6 The box has the grease pencil serial number on the side. The magnum cylinder has 725 stamped. The other cylinder is stamped the same. Somewhere I read the super single six didn't start production until the sixties. The serial number on this gun dates it to 1956-57. I have questions…..