So you mention deer size game, but I'm glad you clarified African game. Here in North America, the .30-30 has killed more whitetail than anyone could imagine.
With that said, I wouldn't recommend it in Africa.
I agree with most that the .30-06 would be the favored all around cartridge, as ammunition is plentiful in most of the world, and it does a good job on most game. My only guidance beyond that would be to not shoot further than 250-300 yards. After that, the bullet tends to lose power and drift exponentially.
For game at further distances, .300 Win Mag or .338 Lapua, but the cost of the tool and ammo are costly. Also, you may not be able to easily find ammo is Africa.
Good luck and happy hunting!