Someone at work told me that shooting with dirty-ish brass is the same as shooting with a fouled barrel (distance shooting). He is on the opinion that brass that is too clean won't shoot quite as well as brass that was tumbled.
Of course, after they're cleaned ultrasonically they'll be resized. That usually involves a lube of some sort that's merely wiped off after sizing. Minute amounts of any residual lube usually takes care of the "too squeaky clean" problem.


















































