Namibia requires a minimum of 7mm or .284 cal for plains game and a round that generates a minimum muzzle energy of 5400 joules or 3,980 ft lbs
Tanzania requires a minimum of .240 cal. for plains game and, for dangerous game the minimum caliber is .375.
Here is the link from which the above figures were taken.
http://www.huntinginafrica.co.za/more-info/minimum-required-caliber/When making a choice when hunting dangerous game understand that you do not shoot what you cannot shoot well. With that in mind and if further discussion comes about, consider the following published statistics.
Muzzle energy of certain .375s
.375 Ruger w/ 300 grain = 4,713 ft lbs
.375 H&H w/ 300 grain = 4,873 ft lbs
.375 Dakota w/ 300 grain = 4,857 ft lbs
.375 Remington Ultra mag w/ 300 grain = 5,073 ft lbs
.375 A Square w/ 300 grain = 5,679 ft lbs
.375 Weatherby w/ 300 grain = 5,224 ft lbs (these rifles can also shoot .375 H&H)
.378 Weatherby w/ 300 grains = 5,699 ft lbs
Compare the above with the following in .416
.416 Rigby w/ 400 grains = 5,179 ft lbs.
.416 Remington w/ 400 grains = 5,115 ft lbs
.416 Dakota w/ 400 grains = 5,553 ft lbs
.416 Weatherby w/ 400 grains = 6,474 ft lbs