Colt Upper?

[stenz]

There are 2 forged stamps on the upper. One is a C and the other is an AF combined in one letter so, I am pretty sure its a Colt upper.

There is also a marking on the barrel that is next to the 5.56 NATO and its says MP? Any idea what that means?

What do you think its worth? Its in great condition and comes with a YHM flash hider.

[BPTactical]

There are 2 forged stamps on the upper. One is a C and the other is an AF combined in one letter so, I am pretty sure its a Colt upper.

There is also a marking on the barrel that is next to the 5.56 NATO and its says MP? Any idea what that means?

What do you think its worth? Its in great condition and comes with a YHM flash hider.

The C marking denotes Cerro Forge IIRC. Without being at my shop I cannot verify the AF marking.
The MP on the barrel denotes Magnetic Particle inspected (Magnaflux). What is the twist rate of the barrel? Chrome bore?
Check the bolt as well. A Colt bolt will have a C stamped on it plus the MP IIRC.

For a non factory rifle it is worth the sum of the parts. Figure 5-600 for the upper and 200 for the lower. That's just me though and what I would pay.

[Graves]

A raised marking that looks like a keyhole is cerro forge, the C usually means Colt. Other Colt markings will be CAF, CH, and CM.