Developed in the early 1980s, the M16A2's parameters were mostly driven by requests made by the United States Marine Corps. These requests included alterations to the stock and forearm, integration of an adjustable rear sight, closing off the bottom of the birdcage pattern flash hider, and swapping out the full auto fire mode for a three round burst mode. Intended to discourage "spray and pray" behavior, the burst mode was considered a good compromise between the desire to conserve ammo while retaining the increased hit probability and firepower of an automatic weapon. While a signature weapon of the U.S. armed forces through the end of the Cold War and up to the War on Terror, the window for NFA registration of these rifles was very narrow. Adjustable post front and peep rear sights, with the A2 flash hider on a "C MP 5.56 NATO 1/7" marked HBAR profile barrel with a bayonet lug and round handguard. "C/M" is cast into the carry handle, with a round button style forward assist and casing deflector integrated into the upper, and the lower marked with a "DoD Eagle" paint mark on the front of the magazine well, "(Rampant Colt)/PROPERTY/OF U.S. GOVT./M16A2/CAL. 5.56 M.M./6146347" on the left side of the well, and the four-line Colt's Firearms Division address next to the right handed "SAFE/SEMI/BURST" selector switch. The bolt head and carrier are both matte black finished, with "C" on the carrier and "MP/C" on the head. Fitted with a checkered pistol grip and a fixed buttstock with trapdoor compartment. A hand-numbered shipping box is included, along with an extra magazine, sling and cleaning tools.