Weaver Mounts Top Mount Base 63B Black Aluminum Marlin/Mossberg/Western Field

The Weaver Mounts Top Mount Base 63B is a rugged 1-piece scope base machined from black aluminum and built to provide a rock-solid mounting platform for Weaver-style rings on a selection of classic rifles. Cut to the tight tolerances Weaver is known for, this Series 63B base features the signature cross-lock design that locks rings in place and resists shift under heavy recoil.

The 63B base is specifically contoured to fit select Marlin lever-action rifles (including the 336, 1894, 1895, and Models 9 and 45), the Mossberg 640, and the Western Field 740. It mounts directly to the receiver and can be used as either a front or rear base depending on the firearm and optic setup, keeping the optic close to the bore for a consistent cheek weld and a natural sight picture.

Compatible with all Weaver-style cross-slot rings (rings sold separately), this aluminum base delivers maximum strength without unnecessary weight. Custom hardened fastening screws are included for installation right out of the package.