The problem I'm having is a bit strange. With the die kissing the shellholder 38 cases are sized perfectly. With 357 cases, and with the die kissing the shellholder, the cases are not sized to the case rim. That doesn't make any sense to me at all to my engineering mind, but I fiddle with it and can't solve the problem. Very strange. Sounds like I'm doing something wrong, but I don't know what.
But, since the die works fine with 38 cases, I'll just buy another die specifically for 357, or another set of dies.