The American Defense AD-B3 modular base is the large base in the B-Series lineup, built to carry a full-size 3x ACOG on a quick detach lever (brand part no. AD-B3-STD). It fits the Trijicon TA01, TA11 and TA31 and scopes with similar ACOG-style bases, including the Burris AR-332 and newer Trijicon RX-30 optics that have three inline mounting holes. American Defense CNC machines it from 6061-T6 aluminum, finishes it in hard coat anodize and uses the patented QD Auto Lock lever. Overall length is 3.5 inches, and the centerline with a TA31 ACOG is 1.62 inches.

Key Specifications

• The base is the large size in the B-Series lineup, intended for full-size ACOG scopes.
• Overall length is 3.5 inches, long enough to support a full-size ACOG body.
• It fits the TA01, TA11 and TA31 ACOG scopes as a standalone mount.
• It also fits scopes with similar ACOG-style bases, including the Burris AR-332 and newer Trijicon RX-30 with three inline mounting holes.
• Centerline height with a TA31 ACOG is 1.62 inches, the reference figure for sight alignment.
• Weight is 3 ounces, as listed by the maker for the B-3 base.
• The base is precision CNC machined from 6061-T6 aluminum, a strong, light alloy.
• It is finished in Type III Mil-Spec hard coat anodize for wear resistance.
• The patented QD Auto Lock lever works on both in-spec and out-of-spec rails with no proprietary tools.
• The mount is made in the USA and covered by American Defense’s lifetime warranty.

Frequently Asked Questions

Which scopes fit the AD-B3? It is a standalone mount for full-size 3x ACOG scopes such as the TA01, TA11 and TA31. It also fits scopes with similar ACOG-style bases, including the Burris AR-332 and newer Trijicon RX-30 with three inline mounting holes.

How long is the base? The maker lists the AD-B3 at 3.5 inches overall length, with a 1.62-inch centerline height when a TA31 ACOG is mounted.

How does it differ from the AD-B3-HD? The maker describes the AD-B3-HD as similar to the AD-B3 but with a second throw lever for added security.

Buy the American Defense AD-B3 Modular Base for Full-Size ACOG, Quick Detach

A full-size ACOG needs a base with enough length to hold it square, and the B3 is sized for that. Order it from our Lubbock, Texas gun shop for fast, insured shipping, and look through our other scope mounts.