AR15 build question

[RNDMEVIL]

I've built an "evil black rifle" from collected parts. Bushmaster complete lower and Model 1 bolt assembly but I bought the upper from my dad's surplus of AR uppers. He's had them for quite some time and they were all in good shape, if a little dusty. Everything fits snug and goes bang every time I want it to. My question is how can I determine the manufacture of the upper? Just for the sake of ending my curiosity on the matter.

 

[EShell]

This site may help:
http://www.biggerhammer.net/ar15/uppers/

Be aware that there are so many makers out there now that you may still not be able to find out.

FWIW, knowing who made the upper is not so much an issue as it may seem, it's either in spec or not, and yours seems to be. I have a dozen uppers and don't know who made half of them.

You may find this interesting as well:
http://www.mdshooters.com/showthread.php?t=4197

 

[RNDMEVIL]

Thank for the links. Couldn't find my "MB" stamp on the biggerhammer site but it's just curiosity. Been curious about a lot over the years. I either figure it out or get over it. Love the post on mdshooters. Makes me want to set up the machine shop in the basement that much more.

 

[Ian Sean]

I was curious myself...found this..

This is borrowed from ar15.com and m4carbine.net.
ID of forge markings. It is not an identifier of the final machining company.

A (splintered) = Anchor Harvey Aluminum

AF = Alcoa Forge

C AF = Colt Alco Forge

C MB = Colt / Mueller Brass

Cardinal (stylized) = Cardinal Forge

CH = Colt Harvey Aluminum

CK = Colt / Kaiser Aluminum

Circle/Crooshairs w/"AR" = ArmaLite

CM = Colt / Martin Marietta

D (stylized) = Diemaco

DK = Diemaco / Kaiser Aluminum

E = Emco

EK = EMCO/Kaiser

E MB = EMCO/Mueller Brass

F keyhole = FNMI / Cerro Forge

FA = FNMI / Anchor Harvey

FK = FNMI / Kaiser Aluminum

FM = FN/Martin Marietta

FMB = FNMI / Mueller Brass

Keyhole = Cerro Forge

L = Lewis Machine & Tool

LK = LAR / Kaiser Aluminum

LM = LAR / Martin Marietta

M (under diamond) = Mueller Industries

PA = Capco / Anchor Harvey

PM = Capco / Martin Marietta

 

[EShell]

E MB = EMCO/Mueller Brass

Looks like this is possibly it; "Mueller Brass"