Looking to get this colt upper off a guy but I'm not sure what model it is to make an offer. On the upper it is marked C mp 556 NATO 1/7 cl, also has the 20" barrel. Any help would be appreciated. He's looking to trade that upper for my Beowulf .50 upper and he'll add $250 cash. Good deal?
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Colt AR
- Thread starter frigate88
- Start date
madcratebuilder
New member
Does it include the BCG? The bolt should be marked MPI and have the heavier FA carrier. The Colt uppers tend to be more of a gray color than many other manufacturers.
BPowderkeg
Moderator
Which I figured stands for Colt Military Police?
CMP means Colt Metal Particle (tested)
Crow Hunter
New member
MP
Magnetic Particle Inspection. (Magnaflux is one version)
You dip the parts in a solution (wet or dry) of iron oxide (rust) & ultraviolet dye. You then put a magnetic field on it.
The field will be stronger at the imperfections/cracks in the material and will attract the particles. This will cause the them to show up under a blacklight.
Colt does this after firing a Hight Pressure Proof Load through the barrel to make sure there are no serious defects.
Almost all of the Colt parts in the gun will have also C stamped or marked on them somewhere. Some might have a stylized D, looks alot like a recycle symbol. Those are Diemaco parts (Colt Canda). I had a 6920 upper that was almost all Diemaco parts one time except the Bolt Carrier.
Magnetic Particle Inspection. (Magnaflux is one version)
You dip the parts in a solution (wet or dry) of iron oxide (rust) & ultraviolet dye. You then put a magnetic field on it.
The field will be stronger at the imperfections/cracks in the material and will attract the particles. This will cause the them to show up under a blacklight.
Colt does this after firing a Hight Pressure Proof Load through the barrel to make sure there are no serious defects.
Almost all of the Colt parts in the gun will have also C stamped or marked on them somewhere. Some might have a stylized D, looks alot like a recycle symbol. Those are Diemaco parts (Colt Canda). I had a 6920 upper that was almost all Diemaco parts one time except the Bolt Carrier.
Does is say "C mp" or CMP?
Mine anyway, is C with a space then an MP which is combined into a single character.
Last verticle of the M is the verticle for the P
C mp 556 NATO 1/7 cl
If it really says "C MP 556 NATO 1/7 CL," then:
C = Colt
MP = Magnetic Particle Inspected
556 NATO = 5.56 NATO Chamber
1/7 = 1 twist in 7"
CL = Chrome Lined
Sounds like the barrel is Colt...Colt uppers have a "C" stamped in the right side, just above the forward assist...
Danco's right. That's what it was. It was C space then mp. I just saw the riffle a few hours ago. The only thing I'm concerned about is putting a colt upper on a RR lower. I know colt has done some different things with their pins. Should I be concerned about mating the 2 together if the pins are compatible?
Crow Hunter
New member
Depends on how old the upper is.
They haven't had the offset screw type uppers for a while.
What does the bolt carrier look like?
Is the back of the carrier a full circle or a half moon? That might give you an idea.
In either case, you can get an offset pin set to use it if you want.
They haven't had the offset screw type uppers for a while.
What does the bolt carrier look like?
Is the back of the carrier a full circle or a half moon? That might give you an idea.
In either case, you can get an offset pin set to use it if you want.