Well....I did not suggest this from a standpoint of superior understanding...LOL. It was a "Been there, Dun that, Got da T shirt"Well I will be stand corrected. it was my lubing process. I went back and wiped all the parts off of the die. Relubed those pieces of brass. Sized them again, and bingo...they chamber. Wow. I feel dumb. Why would lube make such a big deal?