I say both are too light
to handle marginal shot angles remember you pay for wounded game in africa if it bleeds you bought it weather you recover it or not. So that being said opt for a 300 something 338 something or a 375H&H. its better to be overgunned than on the edge of just barrley enough. The real truth is all of your shots are not going to be perfect broadside 100yd propositions.Shoot the heavyist caliber you can be accurate with.Why would you fly 1000s of miles to africa pay daliy fees trophy fees tips and lodging costs and bring a marginal caliber rifle?