Re: Reloading die blanks
Midway sells die blanks. Just do a search for "blank die" or "Callahan".
You can make a bushing neck sizer with the chamber reamer. It would hold the case without any slop, which is a good thing. Even the Redding Competition neck sizer with the sleeve has some play with the case inserted. Making a new sleeve for it would be beneficial.
You might also be able to create a die that bumps the shoulder back a couple 0.001" without sizing the body.