I drilled and tapped with, IIRC, a number seven drill bit and a 1/4-20 tap, then I used a nut large enough to go over the case head (7/8??)
Anyway all I did then was drill/tap, place the nut on the die then a 1/4" fender washer, screw in 1/4" bolt and remove stuck case.
Same thing as the RCBS...