The Weaver #63B Top Mount 1 Piece Base is a single-piece aluminum scope mount designed to simplify setup on a wide variety of rifle platforms. Unlike two-piece base systems that require precise alignment, this one-piece design eliminates that variable—once it's secured to your rifle, your scope rings sit in a fixed, parallel relationship to your bore. That consistency matters whether you're dialing in at the range or mounting glass on a hunting rifle. The silver finish blends with most modern rifle aesthetics while holding up to field use.

Built from aluminum, the #63B keeps overall weight minimal, which is especially valuable on lighter hunting rifles where every ounce counts. The top-mount design places the base directly atop your receiver, making it compatible with a wide range of rifle actions—both modern and older designs. Shotgun and long-range handgun setups are supported as well, making the #63B a practical choice if you're experimenting with optics across different firearm types.

Installation is straightforward: mount it to your rifle's receiver using appropriate fasteners, then add your rings and scope. If you're building a two-piece base system for a specific rifle model, note that base pair sets are available for some applications; check your rifle model against Weaver's base chart to confirm whether the #63B is the right choice for your gun, or whether a paired set is recommended for your platform.

Key Features

• One-piece aluminum construction for solid, repeatable scope mounting
• Lightweight design minimizes added weight to your rifle
• Silver finish matches modern rifle hardware
• Compatible with a broad range of rifle actions, shotguns, and long-range handguns
• Simplifies the setup process by eliminating front-to-rear base alignment concerns

Specifications

Frequently Asked Questions

Is this a complete base set, or do I need to buy a second base?

The #63B is a single one-piece base. Some rifle models are offered as two-piece base pair sets (marked in Weaver's catalog); verify your specific rifle model to confirm whether the #63B alone or a paired set is appropriate for your firearm.

What firearms does the #63B fit?

The #63B is engineered to fit a wide range of modern and older rifle platforms, as well as shotguns and long-range handguns. Always cross-reference your exact rifle model with Weaver's compatibility guide to ensure proper fit.

Do I need to buy scope rings separately?

Yes, this is the base only. You'll need to purchase compatible scope rings and your optic separately.