Now that would be fun!I have shot two grey or common duiker with a .300 Sherwood. It worked splendid, and it was fun to hunt with the little BSA Martini falling block rifle. Incidentally the rifle used to belong to Fred Everett, and his wife Sue used it on Zebra.
Otherwise I can think of few things better than a 9,3x62 with a 286gr solid at 2250-2300fps

I have two single shot rook rifles that would be ideal as well. One is a lovely Steven Grant that is also built on one of the tiny Martini falling block actions. This one is in .380 Center Fire (.380 Long). The .380 Long Colt works beautifully in this little rifle.
The other is a Birmingham gun built by Laurenberg and uses the Westley Richards action. It is in original .44 Winchester Center Fire (.44-40)! Perhaps a stopping rifle for an enraged opossum?
Either would be ideal in close cover for several of the Tiny 10.
the answer is very simple I shoot the damn thing with whatever gun is in my hands when the target appears. end of story very simple. you dont play around trying to reload to a solid or some such non sense you just aim and shoot. If you have alot of gun in your hands as is likely in africa then you shoot back in the guts. and yes it will pretty much cut in 1/2 if its a high velocity rd inside 200yds. IF they are way out there 350yds plus rd will be slowed down enough to just shoot behind the shoulder and not exploded. And FYI I have shot plenty of them most with 300WM and a few with 12 Ga. from range of 30 yds to 420yds. who wants to be carrying a "pea shooter" in africa duh thats dumb carry enough gun to kill whatever target of opportunity pops up and you will be happy all day.