I finally got around to using some 5.56mm brass that was sold to me several years ago as "prepped" and ready to use. Bag marked 500 count, actually contained 650, so I can't scream too loudly. Very pretty, well-cleaned, maybe with pins. Very consistent trim length, that's nice. Chamfering inside case mouth required. The bad part was, when they resized these, they were using an undersized expander button. I seated one bullet as a trial, it drove in with a lot of resistance, never a good sign. I looked at the seated bullet, you could see it was slightly cock-eyed when seated, would not be aligned with the centerline of the bore. So next I had to run the expander button through the 200 pieces I was working on, a tedious chore. I didn't fully resize the case, I just backed the expander rod kinda far out of the die body so only the case mouth would be sized. I've got neck sizing dies, but those are for squeezing them down, not opening them up!
When you buy new brass "in the bag," sometimes you need to do this due to irregularities in the mouths. Like dings. But I don't think I've ever gotten any brass that was sized too small.
When you buy new brass "in the bag," sometimes you need to do this due to irregularities in the mouths. Like dings. But I don't think I've ever gotten any brass that was sized too small.