Ian
Notorious member
It's the cartridges rubbing the bolt there, not gun parts. Perfectly normal for that to be coated with brass. However, if brass is wearing away the coating on the bolt ramp and either exposing machine marks or making chatter marks, explain to me how the bolt has a Mellonite finish. A bolt should skate a file, touch it on one edge there where the brass is rubbing off on the back. If the file cuts it, send it back again and tell them it failed heat treat.