My barrel has been shooting pretty bad lately, 6.5 Grendel 16”. So I broke it down today, was going to clean up the receiver face and see if maybe that would help. As I was cleaning up the carbon on the crown of it, I noticed these gouges just inside. Anyone see this before? I didn’t pay attention to it when I got it new and have no idea how I would’ve done this. Any insight would be appreciated!