I was working on my brass and while measuring the cases, I kept seeing a few thousandths variance. I also notice that went I set them on the bench, some would wobble a bit. I was bored, it was raining, so I took a needle file and filed the entire lot. Just enough to change the luster. Probably wouldn't do this for AR or pistol brass, but for the bolt gun, it made all my measurements more consistent. I'll do this to all my new brass from now on.