The M150 is an Advanced Combat Optical Gun sight (ACOG) designed for the US military's M4 and M16 weapon system. It incorporates dual illumination technology using a combination of fiber optics ...

The U.S. Army latched onto this phrase and began to ... gas-operated rifle fed from a box magazine. The rifle used an ACOG 4X optic and had a 21.3-inch smoothbore barrel. The rifle fired long ...