Hi, I noticed this unusual line inside my bolt carrier yesterday when I was cleaning my gun. The line goes all the way inside the bolt carrier lining. I noticed a slight unevenness on the surface of the chrome lining of the bolt carrier when running a plastic cleaning tool over the line. From the picture you can notice a part of it through the cam pin opening. I don't know if its normal. The rifle is a new Colt AR 15 M4. I would appreciate your opinion.

That's not wear, that's the step-down in the diameter of the bore of the bolt carrier.


...

Normal it’s the gas ring run.

Thanks guys. I paid more than a grand for the rifle and waited a ridiculus three weeks for to pass a background check here in the liberal hellhole of what used to be beautifull Washington State. The area of the sircle seems to be raised a little bit when I run an angled tool over it. I dont know if that matters. That is why i fret over everything that may seem odd as far as wear and tear.