Hey everyone, I have come across two A1 upper receivers that I know very little to nothing about. I believe this were made in the Philippines under Colt or with Colt. I have done some research online and I think I'm getting it all wrong.

Would these receivers be correct for a retro upper build of say a 629?

What is everyone's opinions n these receivers? I have my C7 upper on the way and would like to start buying multiple parts to stash away from the next build. I want a Vietnam era looking build after my 723 or 733 build. I will then do a Black Hawk Down build somewhere between those builds. Looks like I may sell my AK-47 now...Maybe.

Thanks.

For a correct 629/XM177E2, the upper would not have any forge codes. Original upper had the Colt proof marks in front of the ejection port cover. The XM177E2 and XM16E1 had much the same uppers.

http://www.ar15.com/forums/t_3_123/398233_Capco___Martin_Marietta.html

I think I might look at these a bit more. I would like to do a 100% correct build. I know the price and money I might not be able to at this time but I'm going to try to as best I can.

Can someone explain roll marks vs no roll marks and how to tell the difference between these uppers?

I'm enjoying learning about these rifles. What I thought was just an A1 Vietnam era rifle turns out my thinking was very very wrong. So much to learn.

Pics would help

When you say rollmarks, are you actually referring to forge codes (e.g. C K, C H, C M, D K, P M, etc.) that are on the carrying handle, the proof marks on the upper by the port door opening, or are you referring to the rollmarks on the side of the lower receiver?

I think I was thinking of the roll marks on the upper. Okay I understand that now I think.

What is GM or HR? I talked with the surplus place you told me about and I'm going to pick up one Colt and the others are marked either GM or HR.