for a year and a half now I've been using my preban Upper(11.5 with 5.5 fs).  It shoots just fine my shots go where I want, never had a malfunction, If the SHTF this is definately my go to main weaponh for back up.

When I bought it from the gun retailer bushmaster's had a month long wait so I expressed interest in other makes.  He sad he was going to the 2002 shot show in vegas and could probably pick an upper their so I sad ok. We batted around names like OLY,DPMS and others But I think I ended up with an ASA but, I'm not sure because I don't see any obvious markers on the reciever to tell me[:\].  

Is there any manufacturer specific marking on the recievers or barrels that can help me ID this suckerher

No.  Even if it has a mark on it, it will only be the ID of the forge that turned out the raw forging, and all the aftermarket makers pretty much use the same forges. Sometimes you can get a close guess by the color of the piece.  Rock River, for instance uses about the blackest finish in the business, and their pieces tend to be a few thousanths thinner than the others; while Bushies tend to be a couple of thousanths thicker at the bottom ---but even at that it would still be just an educated guess. [:D]

Hi Guys, I also have the same dilemna. I bought my A2 upper used. It looks like a good quality forging, the only marking is on the top right side on the carry handle, very near the sights. It appears to be like a broken "triangle" or like some sort of a letter "A" written triangularly. The only possibility for it is a Bushmaster or DPMS, since they are the only ones available here during that time that the previous owner bought it at a gunshop(He forgot to ask what brand he is buying!!!!)

The forge marking is for Anchor Harvey.  Both of my DPMS uppers have this marking.

The funky looking "A" is actually an A H, for Anchor-Harvey, the forge that built the raw blank.  Just about all the AR makers around have used these blanks at one time or another, so it doesn't really tell you a darn thing about what brand you've got.

Like y'all, I've got an AH marked upper w/no idea of who made it. Looks good, fits right, and for $90 complete w/ sights, dust cover and cocking handle from the guy at the gun show, I don't really care[:D].

Currently, Colt, Bushmaster, Diemaco, DPMS, Oly, "JTD", and others are using [url=forgings.com]Anchor Harvey[/url] forgings for upper receivers and carry handles.