The ACOGs combine traditional, precise distance marksmanship with close-in aiming speed. Although the ACOGs have many features which are very advantageous for military use, they were developed by Trijicon without government funding.

Designed for use with the M16 family, every feature of its mechanical and optical design was chosen for a single purpose: to provide increased hit potential in all lighting conditions -- without failure-prone batteries.

The TA31RCO is an Advanced Combat Optical Gunsight (ACOG) designed for the M16M4 weapon system (14.5 barrel). It provides the
shooter with quick target acquisition at close combat ranges while providing enhanced target identification and hit probability out to
800 meters utilizing the Bullet Drop Compensator.

The TA31RCO incorporates dual-illumination technology using a combination of
fiber optics and self-luminous tritium. This allows the aiming point to be always illuminated without the use of batteries.  The Tritium
illuminates the aiming point in total darkness, and the fiber-optic self-adjusts reticle brightness during daylight according to ambient
light conditions. This allows the operator to keep both eyes open while engaging targets and maintaining maximum situational
awareness. 


Designed to the exact specifications of the United States Marine Corp, the unique reticle pattern provides the shooter with quick
target acquisition at close combat ranges while providing enhanced target identification and hit probability out to 800 meters
utilizing the Bullet Drop Compensator.