Is my Barrel Chrome-Lined?

AR/M4 AR Technical Discussion
1

I just traded uppers with a guy who said his barrel is chrome-lined. I’ve looked into the bore with a bore light and although it’s shiny it’s not bright silverish in color. My other AR that I know to be chrome-lined is bright silver. His chamber has a dull grey around it which leads me to believe it’s chromed.

I don’t have much info other than it’s a Colt A1 20" heavy barrel with 1:7 twist and the rifling looks good. Any help is appreciated.

2

From the sounds of the “dull grey” ring, it sounds like it is HCed… one sure way to find out (without hurting anything) is to take a q-tip with a little cold bluing solution on it, and wipe the area that you suspect is chrome – cold bluing will do nothing to chrome.

3

Thanks K.L. Davis. I’m sorry for being such a newb, but what is “HCed”? It’ll be a while before I can try the cold bluing trick, but I appreciate the info. I’m learning, slowly but surely.

4

Sorry… Hard Chromed :wink:

5

Colt Match Target Barrels were chrome chamber and not chrome lined. Another cost cutting measure that Colt engaged in during the 1990’s. They are said to be very accurate.

6

Is that what I have here… a Colt Match Target Barrel form the 1990’s?

7

Is it a ban model with no bayo/lug or flash suppresor. Is it marked on barrel C MP 1/9 Nato? Does the bore appear to have a chrome circle around it or not?

Colt chrome barrels will have C MP C 1/9 or 1/7 NATO on them. And the Hard Chrome linning is visable at the bore. Shine a flashlight in from the bore you should be able to determine right off if chrome lined or not.

8

The barrel reads C MP 5.56 NATO 1/7 and it does have the bayo lug and flash supressor.

I’ve shined a borelight down the barrel and it seems bright, but nowhere near as bright as my Armalite chromed barrel. The Armalite is like a mirror. That’s what has me wondering.

The chamber has a dull grey ring around it which leads me to believe it has a chromed chamber at least.

I’ve read that Colt made some with chromed chambers without chroming the barrels. Also, it was news to me when I discovered that chrome moly barrels aren’t the same as chrome-lined.

9

I belive you may have one of the Colts you read about. Chromed Chamber and non-chromed bore. C MP C 1/7 NATO would be both chromed bore and chamber…