ID AR15 Upper
Hello,
I picked up an AR15 upper unit at a gun show. The barrel is approx 20" long and the flash hider looks like a cage. It has a forward assist, oval in shape, but no bump out behind the ejection port. The handguards are triangular and the only markings I can find are on the underside of the barrel about 4" back from the muzzle. They are C MP B. The P shares the M so that it looks like one letter.
The seller told me he thought it was a Vietnam era upper that Colt rebarreled with a chrome bore. The bore is shiny and appears unused. Can't really tell but would appreciate if anyone can ID this from what I described. Thanks
Aldo35
I picked up an AR15 upper unit at a gun show. The barrel is approx 20" long and the flash hider looks like a cage. It has a forward assist, oval in shape, but no bump out behind the ejection port. The handguards are triangular and the only markings I can find are on the underside of the barrel about 4" back from the muzzle. They are C MP B. The P shares the M so that it looks like one letter.
The seller told me he thought it was a Vietnam era upper that Colt rebarreled with a chrome bore. The bore is shiny and appears unused. Can't really tell but would appreciate if anyone can ID this from what I described. Thanks
Aldo35
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I take it this is an A2 upper. A Colt A2 upper will have a C on the right side below the rear sight. The barrel markings on early Colt barrels are vague. I would expect it to be marked C MP CB, just the B is interesting maybe someone else has more information there.
The bolt should be marked with MPC and the carrier will have a C on the left side below the gas key.0 -
The "bump" is called a case deflector. Commercial uppers without case deflectors but with forward assists weren't made by Colt until the 80's, according to the site at this link. http://www.biggerhammer.net/ar15/variants/ I'm not sure when the uppers produced for the military had the case deflector added?
Obviously it could have been made by someone else, though not likely.0 -
He didn't mention the rear sight..so I'll have to go with it being an A1 upper barrel/receiver assembly. The A2 F/A is round, and the A1 is teardrop (OP calls it 'oval').
The barrel markings are Colt. I need to know the front pivot-pin size to narrow-down the guesswork, however. Thanks, Joe0 -
Bubba's moved up from Mausers to AR's. 0 -
The C MP B marking was used circa 1972 and means Colt Magnetic Particle (inspected) (chrome) bore. Before that many were marked C MP C with the C meaning Chrome chamber only.
There might be cast letters on towards the rear of the upper in the recess just in front of the charging handle. Also there would be a stylized proof mark on the right side of the upper like this:
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If you can provide the letters by the rear of the upper, I should be able to tell you who made it.
There is a wealth of information on this site:
http://retroblackrifle.com/
I would suggest you probably have a Colt 603 upper that has had a refurb where the barrel was changed.0 -
In addition to looking for those forging marks and proof stampings on the receiver, I'd also suggest looking the front sight base over for forging marks.
You also might pull the handguards and take a look at the entire barrel. Besides markings near the chamber area you may see indications of barrel replacement during a rebuild, such as rub marks in the finish.0 -
quote:Originally posted by Txs
In addition to looking for those forging marks and proof stampings on the receiver, I'd also suggest looking the front sight base over for forging marks.
You also might pull the handguards and take a look at the entire barrel. Besides markings near the chamber area you may see indications of barrel replacement during a rebuild, such as rub marks in the finish.
Yep. Colt will have a tiny 'bell' symbol on the FSB. It's not a stamping, which sinks into the metal, but it's in 'cameo print' meaning the bell sticks out, much like bas-relief. Look for it. Joe0 -
The seller was correct in his assumption, it is a mid '70's Colt 603(M16A1) upper. I have the exact same upper in my collection. It might have been a late Vietnam run, but it is likely a LE surplus upper. The links below will tell you everything you need to know about every aspect of your upper, the first link being exclusively deticated to the 603.
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Please read the Posting Guidelines0 -
It sounds like the M-16 take off I have.
It should have a C-H under the rear sight.0 -
Hi,
Thank you for the reply and website recommend!
You are correct the recommended website describe this as an A1 with chrome bore and chamber. Unfortunately the markings on the receiver are to vague to read even with a mag glass.
I bought this in Hftd,CT at a gun show and guy said it was a Colt rework to chrome to overcome fouling problems they had with earlier AR's. I also picked up a heavy barreled receiver, no hand guards or bolt that was produced by Colt in the 60's. The weapon was called CAR-15 Heavy Assault Rifle M1. It fits nicely on my 60's SP1 but needed a different pivot pin as it forward hole is 0.25 and my SP1 has a 0.315" hole. I ordered a charging handle and hand guards from Sarco's but they are out of the complete bolt carrier. Any suggestions where to buy one. This hvy barrel does not have the forward assist.
quote:Originally posted by CDMead
The C MP B marking was used circa 1972 and means Colt Magnetic Particle (inspected) (chrome) bore. Before that many were marked C MP C with the C meaning Chrome chamber only.
There might be cast letters on towards the rear of the upper in the recess just in front of the charging handle. Also there would be a stylized proof mark on the right side of the upper like this:
[url][/url]
If you can provide the letters by the rear of the upper, I should be able to tell you who made it.
There is a wealth of information on this site:
http://retroblackrifle.com/
I would suggest you probably have a Colt 603 upper that has had a refurb where the barrel was changed.0 -
Aldo, I am glad you found the info you were looking for. If the proofs are hard to make out, the upper was probably refurbed and rebarreled as you describe. It is more than likely Colt, but since it is a Nam era upper refinished post '72, it could also be a GM Hydramatic or an H&R made upper. The way you can tell is if there is still a trace of flashing on the front and/or rear of the carry handle, it is H&R or GM made.
Either way, you have a cool piece of history, have fun with it!
As to the M1 HBAR upper you mentioned having on your SP1 lower, these are VERY rare in original state and seldom seen, EVER. If you have pics of it, that would be awesome, I've never seen actual pics of one other than old Colt stock photos from the '60's. Did you get this upper at the Hartford show also, or somewhere else?? If you don't mind me asking how much you paid for it?? What are the barrel markings?? Sorry for being nosy, I'm just a big retro rifle fan. You can PM me if the thread gets locked before you can reply.0
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