Weaver 48040 Top Mount Base 40A Black - Remington 700/Ruger M77

The Weaver 48040 Top Mount Base 40A delivers precision scope mounting for Remington 700, Ruger M77, and Weatherby Mark V rifles. This machined aluminum base provides the solid foundation needed for consistent shot placement at extended ranges.

What Makes This Different

Unlike standard two-piece bases that can flex under recoil, the Weaver 40A features a one-piece design that spans the entire receiver length. The extended rail surface distributes mounting stress evenly across multiple contact points. This rigid platform maintains zero through thousands of rounds while providing maximum eye relief adjustment for optimal scope positioning.

Key Features

• One-piece aluminum construction eliminates flex between front and rear mounts
• Black matte finish reduces glare and resists corrosion in field conditions
• Precision-machined dovetail slots accept standard Weaver-style rings
• Compatible with Remington 700, Ruger M77, and Weatherby Mark V actions
• Extended length allows optimal scope positioning for any stock configuration
• Drilled and tapped mounting holes align perfectly with factory receiver holes
• Low-profile design maintains clean sight line aesthetics

Field performance remains consistent across temperature extremes and heavy recoil cartridges. The aluminum construction expands at the same rate as the rifle receiver, maintaining tight tolerances during rapid temperature changes. Competition shooters rely on this stability for sub-MOA accuracy requirements, while hunters depend on the secure mounting through rugged backcountry conditions.

Technical Specs

• Material: 6061-T6 aluminum alloy construction
• Finish: Non-reflective black matte coating
• Mounting: Uses factory drilled and tapped receiver holes
• Ring compatibility: Standard Weaver-style dovetail rings
• Weight: Approximately 2.1 ounces
• Length: Extended one-piece design spans full receiver
• Rifle compatibility: Remington 700, Ruger M77, Weatherby Mark V
• Installation: Requires basic gunsmithing tools and proper torque specifications

This base transforms scope mounting from a potential weak point into a precision advantage. The machined tolerances and proven design have earned trust among competitive shooters and serious hunters who demand repeatable accuracy.