This is an exceptional example of a very early Colt M16 type fully automatic Colt Firearms manufactured assault rifle. These original early Colt fully automatic M16 series rifles are very difficult to find on the open market today as most were restricted to either Government sales or Foreign Military sales programs. This example is actually a very early model with the transition markings of, "COLT/AR-15" and "XM16E1" indicating it was produced circa 1966/67 after the Air Force contracts during the early US Army implementation before it was type-classified by the US Army as an M16 rifle. This example has been overhauled/rebuilt by the Annistion Army Depot and is correctly hand stamped on the right side magazine well with "77/3/A". Currently it still retains the early style M16 upper receiver, three prong flash hider with a US Army contract "SAK/MP C" marked SACO-Lowell produced chrome lined barrel. It still retains the early buttstock with no trapdoor, the triangular handguards and two position flip rear sight. It still has the correct M16 fully automatic bolt carrier group with a "MP-C" marked bolt. Interestingly the side of the bolt carrier has been electric pencil marked "#92 634014" and the side of the bolt is also marked "#92", indicting this assembly and rifle were probably issued to a DOD type agency outside of the US Military, where the bolt assemblies were stored separately, but numbered to make sure they retained their original bolt carrier group. These rifles were all produced on the military production line using military grade factory parts. The magazine well is roll marked with the Rampant Colt logo followed by "COLT/AR-15/PROPERTY/OF U.S. GOVT/XM16 E1/CAL. 5.56 MM./SERIAL 634014". Farther back it is marked "COLT'S PATENT FIRE ARMS MFG.CO./HARTFORD CONN./U.S.A." along with the standard "SAFE/SEMI/AUTO" receiver markings. This is an exceptional M16 type rifle that is fully transferable. Magazine absent.