If there was a "Best" of anything, we'd know about it... And I wouldn't have married three times.

For African hunting, as many here have pointed out, one prime consideration is that you may encounter anything at anytime, and a big angry anything running at you dictates what you ought to have in your hands.

So, yes, a Plains Game rifle should be on the heavy side, caliber wise. Any of the various 8x68, .338, 9.3, .375 will insure that you can do reasonably well on longish shots, and save your bacon if faced with the unexpected - provided you have the right bullet up the spout. No real point in trying to quell the animosity of four tons of pachyderm with a Silvertip...

The Woodleigh Hydro is in a niche by itself in these circumstances. It will allow you a decent wound channel on plains game if you are presented with a shot and no time to switch rounds, and will drill through feet of bones (ok, maybe not...) if needed in a tight spot.

In the end, it all depends on the area in which you find yourself, and the critters roaming by.