M16A1E1 upper ?

I tried "ar15.com" , but they have unfriendly pic posting so it goes here. I think I know what this M16A1 upper is I have... but would love to hear more about it.

It looks to be a A! upper. I have one I put together on a RR lower. shoots very well.

look thru here - compare your parts ,

Home Retro Black Rifle

A square , Nice site .. but it sure does not show any M16A1E1 uppers for me to compare.

Your upper was the first design for the M-16A2, but then the Marines wanted the A-2 sights for greater (and easier) accuracy at longer ranges. The A-1 sights could not be easily changed (elevation) to fully use the longer ranges of the new 62 gr. rounds.
Notice that your upper has the brass deflecter of the A-2, the flat handguard nut of the A-1; unable to nake out the handguards, are they round or tri-angular? Is your bolt-assist round or teardrop shaped? What is the twist rate for your barrel?
Some commercial copies of the M-16A1E1 were made and IIRC, Colt made a few also.
HTH

albud ; In every way this is an A1 excepting the burton button ( brass deflector ). This was originally on a refurbished M16A1 lower as issued. A buddy swapped it out for me with a spare A1 upper assy he had managed to squirrel away in case he needed to replace a damaged rifle in case of a short notice inspection of the arms room. This is as it was received in a batch of M16A1's sent as replacement for rifles sent in for repair by the unit. It's not commercial in any fashion. The assist is tear drop shaped for what it's worth - not round like the early assist plungers were ( those round ones could easily cut your palm to hell ! ). Of course it has the triangular handguards - when I got out of active duty and went in the guard it was some years before A2's got to the ARNG level and this was way before then. Barrel is the typical 1-12 chrome lined marked MP under the front sight on the barrel and has the large 'C' about 1 7/8 from muzzle.

I took some better quality pics.

It's in there
http://www.retroblackrifle.com/ModGde/RflGde/603E1.html

Oswago , nope not it. The link you use is for an M16E1 , Not a M16A1E1. Seems data on any transitional rifles/features during the ramp up to the A2 is pretty scarce.

Oops my bad, here's a little info

1981. Colt developed a variation of the M16A1, adapted for the SS109/5.56mm NATO cartridge, and submitted it to the military trials as the M16A1E1. This rifle differed from the M16A1 by having the heavier barrel with faster 1:7 rifling, a different type rear sights (adjustable for both range and windage), round handguards instead of triangular ones, and by replacing the full-auto fire mode with the burst (limited to 3 rounds per trigger pull), to preserve the ammunition.

1982. M16A1E1 is type-classified by US DoD as the "US Rifle, 5.56mm, M16A2".

1983. US Marine Corps adopted the M61A2 rifle.