I have a H&R 12ga single shot Shotgun i got about 8months back cheap from a pawnshop.It looked good in the store tho dirty bought it took it home and its sat since. today i was bored and thought i should really go over this shotgun. briefly looked it over again seemed fine took her apart and started cleaning. And after cleaning much carbon build up i notice the damage. none of it seems super deep when i run a brass pick over it but as its at the throat i thought when not make a post lol was a little hard to get some good pictures without blinding the camera