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: – Colt Coltsman in 223 (Sako Action)(Rear) – Garcia 74 (Rear) – H & R 317 before the 1975 Model (Rear) – Sako Models Forester Finnbear & Vixen (Tapered Dovetail)(Rear) – Savage 2400 (Rear) – Tikka in the Sako design (Rear) – Valmet Tapered Dovetail (Sako design)(Rear) – Western Field 750 (Rear)