Each Weaver Top-Mount Scope 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:Browning Models A-Bolt, A-Bolt 22 Stalker, Medallion (Front and Rear); BBR LA/SA (Rear)Cooey 71 (Rear)Enfield (Cut down like a Winchester 70)(Rear)Marlin MR7 (Rear)Sears 53 (Rear)Winchester Models 70 LA(hole spacing same), 300 Magnum and 70 SA, 670 and 770(Rear)