Weaver's precision-built all steel bases are machined to tight tolerances for a custom fit and a square-cut notch mates to the sturdy cross bolt in every Weaver Detachable ring. Custom hardened fastening screws included. - Fits: - Browning Mauser Actions (Rear base ONLY) - Cil Model 972-C (Rear base ONLY) - Colt 57 (Rear base ONLY) - H & R Models 300 301 330 & 370 before 1973 (Rear base ONLY) - Herters J9 (Rear base ONLY) - Interarms Viscount (Rear base ONLY) - Marlin 455 (Rear base ONLY) - Mauser with receiver ring about 1.410 Diameter(98FN) (Rear base ONLY) - Modern Muzzle Loading Models LK-93 Wolverine Legend Disc & American round receivers (Front and Rear base) - Musgrave models Mark III and Mark IV (Rear base ONLY) - Parker-Hale Models 1000 1000C 1100 1200 & 1700 (Rear base ONLY) - Sears Models 50 & 51 (Rear base ONLY) - Voere Models 2150 2165/1 2165/2 2165/3 & 2165/4 (Mauser Action) (Rear base ONLY) - Weatherby models with FN Mauser Actions (Rear base ONLY)