I have an older SP1. the upper does not have the CM near the rear site, but it does have what appears to be a C surrounded by a square, and a P surrounded by a triangle, near the front portion of the ejection port cover. I know this is A Colt upper because it is the one that came with the gun when purchased new. However; I have another upper that I bought. I was told it was a Colt. It is an A1 with a tear drop forward assist, A1 sites, and no brass deflector. It has no markings on it that I can find. Any help would be appreciated.
The picture was no longer posted, maybe it was too large. Here is a Link to it.

www.angelfire.com/ego/ar15_m16fan/Mvc_010s.jpg

Check Here: www.biggerhammer.net/ar15/uppers/

Mike

Here is the oppiste view of the upper.

Mike, after reading the info on the link you gave. This upper has the sear relief cut like the M16. The SP1 upper, does not have the sear relief cut. Does this mean that my upper is an M16 upper? Thanks.
Tom

www.angelfire.com/ego/ar15_m16fan/Mvc_019s.jpg

Sorry but can't view your pics, so it's hard to say.

Mike

I do not know why, but it will not completlly connect you to the picture if you clik on the link. You can however type the address in the address bar at the top and hit the GO button and it will take you to the picture. The pictures were originally posted. I do not know why they are not showing up now.

Okay, got to take a look at your pics, I can't be sure what it is, some aspects appear to be Bushmaster, but I have never seen a Bushy without a brass deflector so this will have to wait for someone like Chuck w/ more knowledge than I.

Sorry, by the way after I came back from anglefire your "opposite pic" was viewable, strange.

Mike