Is the gas chamber chrome lined?

[A5BLASTER]

Interesting. I'm not sure if there's a coating that would stick to the chrome, or if they remove it to treat a bcg. I'd be surprised to hear that if they do. I don't have any fancy BCGs, I've got two BCM, a PSA, a Joebobs, and a LaRue. All of them are chrome lined. I've resisted the draw to the fancier treated versions as I don't think I could ever shoot enough to wear out a standard M16 Mil spec version.

I will say this a properly done nickoleboron coated bcg will blow your mind how clean it stays and how slippery it is in the rifle.