The Weaver #20A Top-Mount Scope Base (Weaver part no. 48020) is machined for the Mossberg 400 and Remington Model 14/141, giving these classic slide-action rifles a factory-tight platform for a riflescope. Weaver cuts the base from aluminum and finishes it in a black gloss that matches most factory blued receivers. Because it’s machined to the exact screw pattern of these rifles, it bolts straight to the factory holes with no drilling or gunsmithing needed. This is the correct base to start with if you’re mounting glass on a Mossberg 400 or Remington 14/141 for hunting.

Key Specifications

• Purpose-built to fit the Mossberg 400, matching the receiver’s factory-drilled screw pattern.
• Also fits the Remington Model 14 and 141, sharing the same drilled hole pattern.
• Listed as a 1-piece base, so a single component bridges the full mounting area.
• Positioned as the rear base on the receiver for correct scope eye relief.
• Uses Weaver’s To Receiver mount style, bolting directly to the factory tapped holes.
• Finished in black gloss to match most blued receivers.
• Machined from aluminum for a lightweight, corrosion-resistant base.
• Requires Weaver-style rings to complete the mount.
• Ships with rings not included, so pair it with your own Weaver-style rings.
• Cross-references as Weaver Application #20A on the brand’s official fit chart.

Frequently Asked Questions

What rifles does this base fit? It’s machined for the Mossberg 400 and Remington Model 14/141, listed under Weaver’s Application #20A.

Are scope rings included? No, this is the base only; pair it with a set of Weaver-style rings to finish the mount.

Where does this base sit on the receiver? It’s the rear base position, designed to sit toward the back of the receiver for correct eye relief.

Buy the Weaver #20A Top-Mount Scope Base for Mossberg 400 and Remington 14/141

A base machined to the exact receiver pattern keeps a scope tracking true shot after shot, and this Weaver #20A bolts straight to a Mossberg 400 or Remington 14/141 with no modification. Order it from our Lubbock, Texas gun shop and it ships fast to your door, along with more scope bases and mounting hardware.