My brother just got one in 401 power mag, and he made some dies for it, without listening to me.
I was trying to tell him about the brass springs back when it comes out of the dies.
I think he made the sizer die too big.
In the end he borrowed my 40sw/10mm dies.
Maybe he can bore out his home made dies for his 50 Rem rolling block pistol.
We screwed around with some cartridge conversions, but then he happened on some brass that was the real thing.
I know how much pressure guns can take from looking at them, and that revolver is as stout as most 44 mags.