View Full Version : Colt AR 15 A2 Sporter II need some help

December 20, 2009, 10:48 PM
I have inherited a Colt AR 15 Sporter II; shot maybe a handful of times. My Father received a letter from the manufacture stating something to the effect that this Rifle has been missed stamped and could be unsafe. I cannot find the letter (Dad's records are incomplete) which I read nearly 20 years ago. SP 2131**
The first thing that looks incorrect is that it is marked .222, but the barrel is marked MP5.56. I'm not sure but everything I have read is that it should be marked ".223".

Next, is I have someone who is interested in this AR 15, but I do not want to give it away at a regular price if I have something special.

Any and all information will be appreciated.

Thank you, Brad

Bud Helms
December 21, 2009, 04:46 AM
"Any and all information" you get on this piece should be from Colt's, not the internet. :rolleyes:

Contact Colt's and get the real poop. Then come here and tell us the real story.

December 21, 2009, 10:26 AM
Hi Brad.

While Bud is right that Colt is the ultimate authority, this isn't too new for AR shooters.

The stamping on the lower is almost certainly a mis-stamp. Some guys at AR15.com can probably give you the skinny on it, but that's a new one on me. With the AR, though, what is stamped on the lower is essentially irrelevant when it comes to what the gun will actually chamber. There's two sizes of AR lower- the .223/5.56 lower (that will run all kinds of different rounds) and the .308 lower (has a longer magwell because of the extra length). To my knowledge Colt has never made a .308 AR platform rifle.

With an AR, what is stamped on the barrel is gospel. Your barrel is stamped "C MP 5.56 NATO 1/7." The C indicates that it is a Colt barrel, the MP indicates magnetic particle inspection. The "5.56 NATO" is what the chamber is actually cut for, and you can shoot 5.56x45mm or .223 out of it (the size of the two cartridges are the same, but 5.56 runs at slightly higher pressure- you can shoot .223 from a 5.56, but not the other way around; .223 barrels are generally for high accuracy long range varmint style ARs). The 1/7 indicates rate of twist- one turn in seven inches. That's as fast as barrel twists go for 5.56 ARs, meaning your barrel can be expected to stabilize the newer heavy bullet loadings like the Hornady TAP in 75gr.

So your barrel is perfectly normal and actually a desirable one for defensive uses. The lower is indeed mis-stamped, but somebody else is going to have to tell you if you have a rarity or something of extra value- I have no idea.

December 21, 2009, 11:12 AM
colt did in fact make rifles in .222. fairly rare too. yours appears to have been rebarreled or have a different upper altogether.

December 21, 2009, 11:23 AM
you need headspace gauges or a gunsmith.

if they sent a letter stating something is mis-stamped, who knows exactly which part is mis-stamped?

December 21, 2009, 03:48 PM
Very interesting. I would call Colt for the details. They have good customer service once you actually get someone on the phone.

Personally, I would keep it just because it was your Dad's.

December 21, 2009, 10:41 PM
As I thought you fine people would provide me with the general knowledge that I need to get the ball moving forward. I will contact Colt and see what the manufacture can provide me to correctly ID this weapon.

To answer one question; This AR 15 meant very little to my father. He provided me with many more memories of the shotguns and rifles that were handed down to me both before and at his passing. This weapon was a novelty to him and he never shot it. A friend of his shot it, maybe 5 to 6 rounds.

Thank you for all the help. You guys are great for taking the time. I will post what Colt states for your education and mine.


December 22, 2009, 09:53 AM
Yeah, do post what Colt says. The .222 stuff is news to me, but I'd be inclined to trust the barrel- I'm betting it was rebarreled or reuppered at some point; the 1/7 twist is not all that old, and from your pics it looks like your rifle has the older front pivot screw attachment (nowadays Colt really only uses the pins like everybody else).