The Bindon Aiming Concept (BAC) is a both-eyes-open aiming method which allows shooters to acquire, track and hit targets more accurately than with one-eye-closed riflescopes.

With its dual-illuminated reticle, the Trijicon ACOG TA31A provides shooters with a distinct aiming point in all light  conditions – without batteries.  Powered by a tritium-phosphor lamp, the scope’s reticle glows in low-light  conditions, while advanced fiber optics automatically adjust the brightness level and contrast of the reticle in brighter light conditions.  Many models – including the 4x32 ACOG TA31A that’s now available to hunters and target shooters – incorporate the innovative Bindon Aiming Concept™ (BAC). This revolutionary, both-eyes-open aiming method provides you with “instinctive” target acquisition and increased hit potential. And, the scope’s ranging is built into many of its reticles, allowing you to set zero and never worry about it again.  Broad-band, anti-reflective coated lenses provide superior clarity and light gathering capabilities with zero distortion. The ACOG TA31A also offers large eye volume, giving you greater leeway – fore and aft, and from side to side – with which to see through the lens. Of course, once the target is acquired, the ACOG TA31A is a trusted ally to help you zero in on a perfect shot. 

The ACOG TA31A is crafted with a tough, military-grade aluminum-alloy housing and is waterproof to depths of 328 feet – making it nearly indestructible. Only the prism housing moves, so it’s much more rugged than conventional designs. And the ACOG TA31A does not require failure-prone batteries – so you can rely on it to perform in practically every situation.

In selecting the ACOG TA31A, you’re in good company. The world’s very best company, in fact. The ACOG TA31A is the official rifle combat optic of the U.S. Marine Corps. In addition, the Trijicon 4x32 ACOG TA31A is standard issue for all Special Operations Forces, and is the official magnified optic of the U.S. Army.