I use the bushing die to load 22-204, 6mm-204 and can load 25-204's on it but the 204 bushing die wasn't availible when I built the 25-204 and had Hornady make a custom sizer, there stock 250 Sav/257Rob. seating die will work with it.
If ou want to use an expander ball you will need to get the 224 expander stem also as the 204 expander stem is too small to use the 224 expander ball.