Frustrated by not being able to get ammo or cases for the 204 I ordered 222 Magnum cases from Midway. After receiving the cases I tried several methods for forming cases that I hac used in the past. My best solution turned out to be just running the lubed deuce magnum case into the FL size die. Bingo, ready to load and fireform.
Sooted one of the cases and chambered it to check if the false shoulder actually contacts. It did make contact, which tells me that the headspace will be good.
I was trying things like necking up to 6.5 MM and then back down, in otder to have more shoulder. But, that process was going to add several more die passes to complete and without the actual forming dies, it appeared that I would have a lot of shouder colapses.
Once again the K.I.S.S. principle worked best for me.
Now I have to decide whether to fireform with bullseye and cornmeal or just load and hunt with these fireforming cases. What's your experience with the 204?