Ruger® Brand Scope Mount for Mk I, II, II, and 22/45 Pistols Genuine Ruger factory scope mount for your Ruger Mk I, II, III, and 22/45 Pistols. Fits the three screw hole pattern and mounts in front of the rear sight. Features a narrow "22 ring" groove on top of the standard Weaver style sides and slots. See all of our Ruger Mk Pistol Accessories on our Mk Web Page.