Weaver's Top Mount Base is machined to tight tolerances for a custom fit. It offers maximum strength for rings to hold tight and is constructed of aluminum. Fits Marlin 39A; Moss 43, 44, 144, 46BT, 35, 45, 46; Sav 19, 23, and Winchester 75 Target; rear bases compatible with Moss 40 and Sav 3; front and rear bases compatible with Sav 93F w/heavy barrel/93, 93FVSS, 93R17, Mark II/64/CUB.
