Manufactured between 1973 and 1982, this vintage pre-1986 Colt M16 lower receiver has been upgraded with a later production A4 patter upper receiver assembly outfitted with an A.R.M.S. SIR free-floating handguard, giving the flexibility of current "modern sporting rifle" design in a fully transferable automatic weapon. Post front and pop-up adjustable two leaf rear sights, closed-bottom birdcage flash hider on the 1/9" twist barrel, and a bayonet lug. The lower has the traditional Colt model markings and address on the left side, with a "SAFE/SEMI/AUTO" marked right-handed selector switch, checkered pistol grip, and a Bushmaster brand 6-position telescoping buttstock. The bolt carrier and bolt head are both matte gray finished, and a one piece buffer is installed. A canvas soft case is included.

Very fine as assembled, with 90% of the matte black phosphate finish, showing a number of scratches and dings on the lower receiver and lighter handling marks on the upper receiver and stock. Mechanically excellent. NOTE: This weapon is a National Firearms Act (NFA), fully transferable Class 3, which is registered with the Bureau of Alcohol, Tobacco, Firearms and Explosives, (BATFE) under the provisions of 18 U.S.C. Chapter 44 and 27 CFR part 478.