Bonanza

I picked 450 3 1/4 because it would have made the others unnessary had it not been for the British Gov't banning all 45 cal. ammo in India and the Sudan in 1905. The ban spawned a whole host of chamberings that duplicated the 450 3 1/4. power.. The .470 Nitro being one of them.
As for the 500/450 and the 450 No.2 these are big rounds and make carrying them and the rifle a real chore in the field..
My take is if you pick any of them your going to have what is needed for what ever You come across or what ever comes at Ya'll..
My choice is the 450 3 1/4..
AK