I had them do a small car radiator for me with Graphene for good heat rejection and it turned out fantastic, so I was going to send my 870 receiver to them but now that you mention that is suspect. I would definitely not want them to do that to the internals because there is almost zero chance I am taking it off without damage to the receiver.Crappy workmanship. I had them do a G19 slide, and instead of coating just the outside of the slide, they sprayed the inside also...and got it so damn thick that i couldn't even reassemble the pistol. Also had to ream Cerakote out of the firing pin channel opening.