That's too bad. I wish you were closer. I would let you test it for yourself on actual gun parts. The Cerakote I know, properly applied, will not rust, cannot be knocked off with a hammer, scratched or chipped without removing the metal under the coating. Even 320 sand paper takes a bunch of work to get it down to bare metal on a smooth surface. Over a sharp edge you can get down to bare metal pretty easy.
The coating should be as tough as whatever is under it. Over tool steel it's incredible. I put it on a set of vise grips. You can destroy grade 8 bolts with those jaws and it took quite a lot of use to get the very tips of the jaw teeth exposed.
