Since each firearm manufacturer has their own proprietary mounting rail design, each ring model must be machined to exacting tolerances for proper fit and function. Because of this, the Warne Ruger Rings are able to fit right onto the receiver’s dovetail with no need for a mounting base. The Ruger Fixed Rings are available in two different styles to fit either the Ruger #1 receiver design (which includes the Blackhawk and Mini 14 models) or to fit the tapered receiver style like the Ruger M77, Hawkeye & Super Redhawk. The Ruger M77 style rings are packaged as two different heights to accommodate the tapered mounting surface on this firearm. Lastly, the Ruger Fixed Rings utilize 4 T-15 Torx style socket cap screws for secure and permanent optics mounting.