I will patiently hang on for our friends from the old world, in the meantime I'll notice for this part of the conversation -- that 'Bombe' or H.V. loading seems to accomplish this via a lighter bullet, not necessarily an exotic 'hot load'.

Otherwise it looks like a
196gr bullet at ~2500 or so FPS
227gr bullet at ~2300 or so FPS
or
187gr bullet at ~2700 or so FPS
for the 'Bombe' or H.V. load

From my experience with the BLE double rifle (which had 26+" barrels) and the Woodleighs, 2500 FPS is about right in real world shooting-to-regulation perspective.

Cheers
Tinker