The .375H&H built it's reputation on high speed (2,600fps) 270gr. soft points for plains game, and on the 300's softs and solids (2,400fps) for dangerous game.

The 9.3x62 (according to John Taylor) built it's African plains and dangerous game reputation on 286gr. soft and solids at a muzzle velocity of 2,175fps. In the 1920's, he noted this speed was increased to it's current level of approximately 2,340fps for the 286gr., which he stated was not necessary - that the old ammo killed ALL of the animals just fine at the initial speed. (incidentally, in a 9.3x57- either M96 or m98, the original, wonderful 9.3x62 ballistics can be exceeded)

The .333 Jeffery, with 300gr. at 2,150fps also impressed John Taylor greatly.

I'm not professing to knowing anything about hunting in Africa, but, question, did the game become tougher? I do think the dangerous animals have become somewhat smaller (might be immaterial, though) as far as Trophy size is concerned.