Weaver Top Mount Scope Base #40A — Aluminum, Black

The Weaver Top Mount Aluminum Extension Scope Base #40A is a one-piece top-mount designed to provide a stable platform for Weaver-style rings on a variety of bolt-action rifles. Machined to tight tolerances from aluminum and finished in black gloss, this base uses the Weaver cross-lock design to secure rings against recoil. It is specified for Remington 700 pattern long and short actions and a broad list of compatible receivers as indicated in the manufacturer’s fit notes.

Key Specifications

• The model is #40A and is sold as a single unit.
• The material is Aluminum for a balance of strength and light weight.
• The finish is Black Gloss for a low-profile appearance.
• The product type is a 1-piece top mount base designed to attach to the receiver.
• The overall length measures 3.50 inches as provided in product dimensions.
• The overall height measures 0.85 inches per the supplied specification.
• The overall width measures 1.65 inches per the supplied specification.
• Rings are not included with this base.
• The required ring style is Weaver-style to mate with the cross-lock notch.
• The elevation is specified as 0 MOA.

This compact, one-piece Weaver #40A base offers a durable, precisely machined interface for Weaver-style rings and a wide range of bolt-action rifles, including Remington 700 pattern actions. Its aluminum construction and factory finish make it suitable for replacing a worn base or installing a stable mounting platform without altering the receiver. Choose this base when you need a straightforward, proven mounting solution that prioritizes fit and reliability.