Nobody makes bases to fit as many guns as Weaver. Yet each base is machined to tight tolerances for a custom fit. They're 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. Custom-hardened fastening screws come with every Weaver base.One piece base used on:- Marlin: 39A round bbl** One piece base mounts with two set screws and may require drilling and tapping. Newer gunds are factory drilled and tapped.
