Manufactured 1973-1982, this is a Colt M16 selective fire rifle upgraded to "Model 649" configuration. An evolution of the Model 607 "Commando", the 649 incorporated feedback from field testing, retaining the XM177 flash suppressor, while slightly extending the barrel to further limit noise and flash. Post front and two-leaf windage adjustable rear sights, "C MP C" marked barrel, ribbed round handguard, checkered pistol grip and two-position telescoping stock. The upper receiver has a short casing deflector and no forward assist, with "COLT/M16" markings on the left side of the magazine well and Colt's Firearms Division address on the left just ahead of the auto sear pin hole. The bolt carrier is serrated for a forward assist, with an "MP" marked and phosphate finished bolt head. With soft case.

Developed in response to soldier feedback on the CAR-15/Model 607, the XM177 flash suppressor was intended to reduce the intense muzzle blast created by running 5.56mm rifle ammunition through a short barrel, as well as provide additional back pressure to assure function of the gas mechanism. Overall length is about 4 1/2 inches, with laser engraved markings on the side and an integral "birdcage" flash hider at the end. Internally, a short segment of perforated tubing vents into a small internal expansion chamber; it is primarily this feature that makes it a silencer in the eyes of the BATFE.