I just finished loading my first 50 9mm yesterday... and in the mail came a RCBS case gauge I had ordered! Ran all 50 thru it, 5 stuck a little and on closer inspection had a slight bulge at the bottom that sizing didn't take out. They'll probably work, but now it won't be a surprise. I had already plunk-tested a random sampling, mostly to be sure my dimensions were workable.

I'm sold... get a case gauge!