If I should choose "onegun" for africa I would take my .416Rigby or .333Jeffery...both calibers have a very good reputation upon all game...just like the .375 H&H.
Bror Blix were asked once if he had to choose one gun for all, and he replied: " .318 Westley Richards". I think I read somewhere that John taylor said that the .318 WR penetrated more than anything else. It appeares to me(without personally having experience in african game yet)that the old hunters preferred PENETRATION above anything else. Sir Samuel Baker hated hollow pointed bullet
and preferred solid lead bullet in all his hunting, either 10 bore DR or the .577ex, because penetration was back then a key factor for succes.
If shooting a frontal shot on elefant, which bullet would have best chance of getting to the brain of the two poll calibers? Both calibers can choose the best bullet available. Distance = x.