My Cartridges of the World, #9, lists the three versions as Black, Nitro for Black, and Nitro, all in the same cartridge, with bullet weights from 210-270g in the Black load, to 400g jacketed in the Nitro load.
I think that a 350-400g gas check lead bullet, at 1600-1700fps, would be a peach.
Tony
-------------------- Flinch ? Wot flinch ? Gunsmithing is my PASSION.