The RU-MK II and RU-R triggers are precision engineered upgrades for Ruger rifles, crafted from A-2 tool steel. They undergo investment casting, heat treatment and drawing to achieve a Rockwell hardness of Rc 50-55, ensuring durability and reliability. The radius ground sear surfaces reduce creep for a smoother, consistent trigger pull. These triggers are easy to install without complex modifications. The RU-MK II fits Ruger M77 MKII rifles with a 3-position safety, while the RU-R replaces non-adjustable triggers in 77/22 and 77/17 rimfire rifles. Not suitable for V/T models with a 2-stage trigger, these triggers offer adjustable weight of pull and factory safety compatibility for a customizable shooting experience, enhancing performance and safety. Replacement trigger compatible with current Ruger bolt action rimfire models 77/.22 and 77/.17, including the Hornet variant, is also suitable for .44 Cal, .22 Cal and .357 Mag models Operation for right or left hand use Includes comprehensive instructions, a hardware pack and a wrench to facilitate straightforward user installation Pull weight range - 14 oz - 2.5 lb