I think that most of the rifles carried on safari are quite a bit heavier than the ones that are carried in the woods here. A full stock and forearm of heavy walnut, enough steel in the receiver and barrel to handle the full strength loads and it may even be a double rifle with just that much more steel in it. Also, shooting offhand while standing can take much of the " punch" out of the recoil. Much easier on the body than sitting or prone with the same load. As long as you have the stock firmly welded and lean into it a bit (wingshooter style) you will be fine.
A .375 H&H double barreled rifle would have no more total recoil than a 308 with a synthetic stock. Even a 405 Nitro is manageable.
Of course, around here we don' t commonly use gun bearers to follow us around and tote our shooting irons for us.
Chubber
Just an observation:
Hunters in Africa must consume lots of vitamins, drink fortified water, eat nails for breakfast, and sleep in the dark compared to their North American counterparts -- how else could they handle the rifles they shoot over there without complaining about it?