I've just run into a strange situation. I have a brand new, unopened box of Hornady .30 caliber crimp on checks......that fall off my boolits when sized. I finally stopped fighting it and measured the o.d. and it's .319-.320. A Lyman .30 caliber measures .312 and seats tightly, so I'm suspicious the Hornadys are for a larger caliber and were funneled into the wrong box.
Could someone measure a Hornaday .30 caliber for me and post back here? If they are indeed wrong I'll call Hornady and see about sending them back for the correct ones.