Home Forums Hunting & Shooting AR and Tactical Rifles What kind of upper is this?

I ran across a clean used upper reciever and am not sure exactly what Im looking at as being a AR rookie..its marked as follows..

C MP CHROME BORE...it has a flash hider and a bayo lug...

All info appreciated..any idea what the twist is??

Colt barrel, probably a 1/12 twist. Need to know what length, profile and receiver is on it.

I believe its a 20" standard profile..from what Ive researched it as A1 sights. no lower just a upper. No bolt, Now if I but it can i just drop my bolt in and go?? My lower is a Fulton..

If by standard profile you mean .620 in front of the gas block then you probably have a standard A1 upper and 1/12 is most common. The later A2 govt profile was heavier in front of the gas block but as far as I know were always marked C MP 5.56 NATO 1/7 or such.

You could possibly have a larger pivot pin hole, measure it and if it's bigger than .250 you will need an adapter to use your Fulton lower. I stongly reccomend Colt's adapter because they have a flat side milled and keeps them from rotating, possibly breaking your upper or lower, like some of the others out there.

Should be able to use your bolt since you stated good condition. Alot of National Guard unit's swapped virtually brand new A1 uppers out for M4 or A2 uppers to go to Iraq a few years ago, several of them made it to gun shows as new...

But you need to know, there are some out there that have been used on full auto and worn smooth out by the military. Some of those barrels and bolts wind up on various equipment exchanges/classified ads. A "FIELD" headspace gauge from Brownells is a handy item to have.
If it came with triangle handguards dump those and get some A2 handguards or if it shoots, install a float tube on it. Some of them shot pretty good for a chrome lined barrel.

It does have triangle handguards..how do I change them out?? and is a set of handguards all Id need?

Just pull down on the delta ring, it should be flat shaped next to the receiver and has a spring under it. It might take quite a bit of force but it will come down, pry out the top then pry out the bottom.

Yes handguards is all you will need. And while the triangle handguards will work, they will pinch the crap out of your hand. Besides they are kind of brittle and feel like crap to hold.