A gun should do the same damage as another gun given it’s setup the same.

A coachman with the same mods as another coachman should do the same damage.

But make it “Rarer” and suddenly it does more damage? How?

The receivers in Fo4, I could forgive for game-play purposes, maybe you could reload your brass with more powder or whatever, but the rarity system just doesn’t make sense, and honestly pisses me off.