Need a little help with this, got it new in wrap without much info other than its a "legit colt" upper. What I've found is that the upper receiver has the M16 sear relief as pictured here: http://www.biggerhammer.net/ar15/uppers/searrelief_ar15_m16.jpg

The upper itself just has a C and a keyhole on the assist side. It is flat top. Barrel is 14.5" with a production date of 09/11 stamped near FSB. Also barrel is stamped C MP 5.56 NATO 1/7.

Let me know if any other information would help. I'm really curious to find where this came from model wise. From what I can tell it seems to be nearly identical to a military issue m4 upper?

What is the barrel profile, if you have a government profile barrel that would be identical to the M4 uppers used in the military.

Sounds like M-4 to me. Pics would be helpful.

As others have mentioned, more than likely, it is an M4 upper.  It will depend on the barrel profile, however these are the most common and belong to the following model numbers:

LE6921 - Semi-auto only Commercial/LE SBR
RO977 - Commercial/Export M4 Carbine S-1-F
RO979 - Commercial/Export M4 Carbine S-1-3
RO920 - USGI M4 Carbine S-1-3
RO921 - USGI M4A1 Carbine S-1-F (discontinued in favor of the RO921HB - with a medium (heavy) contour barrel and M203 mounting flats - commonly known as "M4A1" or "SOCOM" profile barrel)

Production date September, 2011 (at least for the barrel) and using a Cerro Forge raw forging machined at Colt.

~Augee

Hey, it is government profile. Here are some pics:

http://imgur.com/a/jdIC1

Standard M4.  Any of the above model numbers will apply.  

The RO920 is the military M4, so this would be identical to that.  

~Augee

awesome, thats what I was thinking. guess I made out good for $450 without BCG/CH. thanks for your help!