I've had a Colt lower for quite a while now and been waiting for the right time to get an upper for it.  Someone I met has what he says is a complete, new Colt 16" upper for sale at a really good price (about $400 less than what's listed on SAW's website).  I need to know what to look for on this upper to confirm that it, all the internals, and the barrel, are indeed genuine Colt.  I hope some of you Colt guys out there can help me out with this.  Thanks in advance...

Colts barrels are ,usually, "C MP xxxxxxxx". also the upper should be marked with a C near the rear sight.
of course, the most important thing is the C that means Colt.

Bigger Hammer . net has a lot of pics and info

Most Colt uppers have forge markings of the letter 'C' then the marking of different forging companys at the right side of it.

There are some with a different style 'D' letter which are Diemaco (Canada) which is owned by Colt.


Here are some photo's in this thread, look lower down the page for the uppers and barrels section.

www.ar15.com/forums/topic.html?b=3&f=12&t=223495


Here are more info about Colt uppers and barrels, there are more info on models and variations there.

biggerhammer.net uppers website link

biggerhammer.net Colt AR-15 FAQs website link

Great info guys, thanks...