I contacted CH4D and got a .240 Wby case sizing die. It uses a shell holder without the slot, essentially a flat platform to push the case into the die. A rod is used to tap the case out. It take a lot of pressure to swage a 25-06 case into a .240 case, as the belt is formed by squeezing the case body. There is usually a ring of sheered brass to be pealed off the newly formed belt.
Ken Howell notes (in his excellent Designing and Forming Custom Cartridges) pretty much the same thing:
"This case definately needs the RCBS belt-forming die to swage a belt into .25-06, .270, .280, or .30-06 brass, and form dies."
My guess is that the two dies Mr. Howell mentions probably cost ~ $150 dollars. .240 Roy brass is something like $2 per hull, right? So if you are wanting more than 75 cases, then the dies and forming process pans out economically.
