American Defense AD-B3 Modular Scope Base - Picatinny-Style Standard Lever, Matte Black Finish

The American Defense AD-B3 modular scope base is a large-format Picatinny mount engineered for full-sized 3x power ACOG scopes and compatible optics. If you're running a TA01, TA11, TA31, or similar ACOG-style base optic on an AR platform rifle, this base delivers the rock-solid repeatability you need for duty, hunting, or tactical work. Machined from 6061 T6 aluminum and finished in hard coat T3 mil-spec anodize, the AD-B3 is built to last and sized at 3.5 inches to balance a low-mounting footprint with plenty of rail contact.

The standout feature here is the patented QD Auto Lock Lever system, which locks down securely on both in-spec and out-of-spec Picatinny rails—a real-world advantage when you're dealing with rail variations across different AR builds. Beyond direct ACOG mounting, the AD-B3 also accepts American Defense modular risers, giving you the flexibility to adapt the base for other optics or mounting heights as your setup evolves. That modularity means you're not locked into a single configuration.

American Defense's engineering shows in every detail. The precision machining and mil-spec anodize layer mean this base will handle field use, recoil, and weather without flexing or losing zero. Whether you're building a patrol rifle, a hunting AR, or a precision platform, the AD-B3 is the kind of foundational component that justifies its place in a quality build—it's not flashy, but it works.

Key Features

• Designed for full-sized 3x power ACOG scopes (TA01, TA11, TA31) and compatible ACOG-style bases
• Patented QD Auto Lock Lever system works reliably on in-spec and out-of-spec Picatinny rails
• Accepts modular risers for optics and height flexibility
• Precision machined from 6061 T6 aluminum for strength and repeatability
• Hard coat T3 mil-spec anodize finish in matte black
• 3.5-inch overall length provides solid rail contact

Specifications

Frequently Asked Questions

What scopes fit the AD-B3 base?

The AD-B3 is the large modular base designed to mount full-sized 3x power ACOG scopes directly, including the TA01, TA11, and TA31, as well as scopes with similar ACOG-style bases such as the Burris AR-332.

Does the AD-B3 work on all Picatinny rails?

The patented QD Auto Lock Lever system is designed to lock down reliably on both in-spec and out-of-spec Picatinny rail systems, giving you consistent performance across different AR platforms.

Can I use this base with risers for other optics?

Yes. The AD-B3 is modular and accepts American Defense risers, allowing you to adapt the base for different optics or adjust mounting height beyond the direct ACOG configuration.

What's the difference between the AD-B3 and other American Defense modular bases?

The AD-B3 is the large base in American Defense's modular lineup and is sized specifically for full-sized 3x power ACOG scopes. The AD-B4 is their largest option at 4 inches; smaller bases like the AD-B2 are designed for mini or lower-magnification optics.