It is dark grey
Has a C forged
Below that is a MB forge mark
Has a 4 above the gas tube entrance,looks like my other 4s.
What is it and what is it worth?
I got it for a pittance with several A2 uppers.
The M4 stamp has me stumped as I have never seen one on an A2 upper.
It does have the feed ramp cuts.
You just described the upper on my Colt Match Target Lightweight.
Does yours have the feedramp cuts in the lower?