Originally Posted by boomtube
Crank your sizer down another 1/16 th of a turn.
"How do I do that? It's already bottomed out on the shell holder."
Okay, good question. But first, is it "bottomed out" on a raised ram with a case in the die or empty? Most folks do it without a case and that's a mistake. You want the contact to occur with the press fully stressed with the pressure of resizing.
IF you are bottomed correctly, you need to slightly modify the die with a little grinding, enough so you can get the case inserted another 2-3 thousanths. You can do it so easy, maybe too easy, possibly leading to excessive shortening. That's not too bad, per se, but it does call for you NOT to bottom the die on the shell holder later.
IF you choose to grind the die, remove the decapping spindle and measure the full length of the die body with a caliper. Then grind away no more than two thousants of the length. Clean the die and try sizing again. If the cases still don't fit, do it again until it does.
OR, you can grind off the top of the shell holder. I don't like that appoach but it's a personal thing, if it seems the die is the problem, I fix the die and leave the shellholder alone..