Just took out this little gem. It is circa 1969-1970. It was manufactured by Colt right about the time they did away with the AR designation and moved to the M16 designation. This one is special to me. I have a copy of the receipt from Colt identifying it as a 639. The gun is roll marked M16. The 639 was issued to special ops in ’68 or thereabouts, had the collapsible buttstock, 11.5″ barrel, and moderator. This “639” (as identified on the receipt with the S/N of the gun) has the collapsible buttstock and 11.5″ barrel. It does not have a moderator but rather a flash hider. Without the receipt, I would suppose it to be a 16 with a Colt upper that was changed after leaving the factory. With the documentation it appears this gun left the factory in this configuration, listed as a 639 on the receipt, and no moderator. I believe the prices reflected on the receipt are in the $37000range. I plead guilty..I put the scope on the rifle (got too much stuff laying around and figured it would not get misplaced by putting it on the gun). I purchased this gun sometime around 2010 and decided to hold onto it. I tend to like the unusual hard to find items and this one fit right in rather than having a standard A1, etc. As to value, I have had differing opinions but am quite sure it is worth a bit more than the original Colt price of $37000 Anyone wanting good info on the various Colt 16’s should pick up a copy of “The Machine Gun Dealers Bible” if you get the chance. I didn’t have a pic of this rifle on this computer so am posting a pic with a few different MG’s including this rifle.