bobm
Silver $$ Contributor
Could be lead buildup in the bore"Nothing a bronze brush wont fix might need some iosso paste too."
I might start off with a square of 120 grit wet or dry paper wrapped around a Parker-Hale jag first.
Optical illusion...is it raised bumps or pits? The surface view outside the magnified view suggests pitting.
Could be lead buildup in the bore

