I have only seen one barrel set that looked dangerous to me. It is a friend's Rem 1894 and has a pit or several pits in the chamber that are about 3/16" dia and over half the chamber wallthickness deep. Any 'smudge' 'roughness' or 'frostyness' wouldn't give me pause to think of safety. Keep in mind...engravers (factory and "upgrade") carve deep, sharp cornered lines on the outside of the chambers all the time... and the outside of the chamber is more highly stressed than the inside of any part of the barrel.
