Airgunner,
the only experience I have with reloading 50 BMG is with the Dillon BFR. Hands down a serious monster of a press and perfectly suited to the 50 BMG cartridge. Haven't tried the others, but I'd be a bit dubious about them. You're asking a lot from a press with cases this big, and requireing this much pressure in sizing ops. Wouldn't surprise me at all if running 50 BMG cases through a lighter press wound up springing or otherwise breaking them.