At the end of the day the shine does nothing for performance, but then too neither does a polished finish or engraving on a gun. It all comes down to appearance. As long as it is clean you are fine. All of my rounds get a good polish after they are loaded simply to make them look good but by the time they get put to use the oxidation has taken over. I don't know why I bother. Habit I guess. Either way there is nothing wrong with a post loading ride in the tumbler.