Ruger complete magazines here are rimfire: .22 LR 10-round magazines for Mark II, Mark III, Mark III 22/45, and Mark IV 22/45 pistols, plus LX-1 and BX-1 rotary magazines. They suit Steel Challenge and rimfire pistol matches where feed reliability through a long string of fast shots matters more than anything else. Confirm your exact model and generation before ordering, and keep a numbered rotation for match day. Fast same-day shipping on most orders at Shooters Connection.