For what purpose are you using a case gauge?
I've probably loaded 40 or 50 thousand rounds of 9mm and 45acp, not to mention equal amounts of 38 special and 357 and have never needed one, nor has a pistol case ever been trimmed.
I'm not saying you're doing a bad thing- but why gauge each case? In a situation where you're going to carry, I can see it (or just use factory ammo for those occasions). You are spending a lot of time gauging rounds that headspace on the case mouth.
Again, I'm not criticizing, you probably have a good reason for doing so, I am just curious what it is. No offense! Just my curiosity working.