AM DEF LRG BASE FULL SIZE ACOG QR

Description

The American Defense Manufacturing B3 Modular Base is built specifically for Trijicon ACOG sights, solving a real problem for shooters who need to move a full-size ACOG between rifles without losing zero or spending time with a torque wrench. The mounting footprint is sized for the larger ACOG body, so it seats the optic properly rather than forcing it onto a base designed for smaller prism sights.

The core of the design is ADM’s patented QD Auto Lock Lever system. A single lever motion locks the base to any 1913 Picatinny rail and releases it just as quickly, while the internal mechanism self-indexes to the same position each time. That repeatability is what makes tool-free removal practical in the field rather than just on a bench — if your zero shifts when you reinstall the optic, a quick-detach mount is a liability rather than an asset. The Auto Lock addresses that directly.

The base is machined from a single block of 6061 T6 aluminum, which keeps weight down while maintaining the rigidity a fixed-power optic like the ACOG needs to hold its point of impact under recoil. A Type 3 hard-coat anodized finish protects the aluminum against corrosion and surface wear in wet or dirty conditions without adding meaningful bulk. American Defense Manufacturing backs the B3 with a lifetime warranty.

This is the Standard Lever configuration in black. ADM also offers the B3 in a Tactical Lever variant and in Flat Dark Earth — worth noting if you’re matching existing hardware on a build.