Just looked at the muzzle of this barrel, and I noticed some discoloration and what I believe to be some pitting at the end of the muzzle. I tried brass brushing it, but that didn't do too much. I ran patches down and noticed that the spot where the discoloration is located, it get's tight (not unbearably tight however). The rest of the bore is mirror shine except this area. Any fixes for this issue? Should I just try to keep shooting and see what happens? Does this effect accuracy in a noticeable way?