Quote Originally Posted by SomeOtherGuy View Post
This is logical and reasonable. However, the shortcut to addressing this is seeing whether X company's nitride barrel shoots well, ideally by reading reviews from earlier purchasers. It seems to be quite possible for a company to make a quality nitride barrel with a sufficiently smooth bore that many people report very good* accuracy with several brands, including AR15 Performance and Faxon.

*I don't say "match" because that doesn't really mean much. If your skills and ammo choice allow sub-MOA accuracy you have multiple factors to consider in maintaining or improving that, and you're probably looking at well made expensive barrels anyway. There are certainly sub-$200 " 'match' " barrels in the market, but probably not so many sub-$200, sub-MOA barrels.



From reading on this topic it seems that just a few live shots in a barrel will cause microcracking in the throat, and nitride treatment after that has occurred is probably a bad idea. Better sticking with makers that fully polish the bore during manufacture.

Also, I have not read of any company that is able to nitride a barrel + barrel extension unit without causing torque issues. Most companies drill the gas port after nitriding. I have an AAC 300BLK barrel that appears to have nitride treatment on the gas port (meaning it was drilled before nitriding) but I'm not certain, and it also has an unusual looking barrel extension with a possible seam running around the circumference of the largest diameter part.

I imagine it would be possible to machine the barrel and extension area from a single piece of metal to avoid this issue, presumably at much greater cost than separate machining.
Maybe Mr. Nathan of Faxon can tell us if nitriding a barrel after breaking it in is a good idea. I'm sure there are ways to prevent the loosening of the barrel extension or just removing it entirely then repinning it. It probably isn't cheap.