Not having hunted Africa my idea would be

2 gun battery, 270win or 303-those MK5 Jungle carbines are nice and light and a 416Rigby.

3 gun battery 22rimfire or Hornet, 270, 416 Rigby.

If only plains game then

22hornet and 35Whelen- with some Woodleigh 225 grain Hydros for anything nasty that turned up- if I couldn't get my 35Sambar in due to headstamps not matching calibre markings on barrel.