Thanks for the great info Daryl.
Sectioned bullets can really tell us a lot about expected terminal performance.

I doubt that any more 270gr RN Hornadys will be forthcoming in Australia, so I will be onto Woodleighs after load development and case-forming is completed. Haven't checked yet, but assume the Woodleigh 270gr RN is designed for the .375 Nitro Express, so expected velocity should be quite a bit less than for the H&H cartridges. Those bullets should have a thin jacket and will be bonded-core of course. They will be my hunting loads.

9.3x57:
I'm hoping to develop loads that are buffalo-capable, with care. They will get a field-trip or two during this coming dry season.

BTW, I should add that the Mannlicher Schönauer has the rotary spindle magazine, and works best with 270gr RN bullets. Haven't tried it yet, but I may not have the option of different bullet lengths, or even different ogive shapes, with that rifle.