Weaver Top-Mount Scope Base #36 Matte Each Weaver base is machined to the tightest tolerances for a custom fit. They are designed to fight the effects of recoil with a square-cut notch that precisely mates to the sturdy cross bolt in every Weaver detachable ring.Fits:BSA Model Monarch Medium Action in 222, 243, &l 308 (Rear) and CF2 Monarch Long Action in 7mm, 270, and 30-06 (Rear)Churchill Highlander (Rear)Enfield (cut down like Remington 721 (Rear)