Attachment 212231 Here is my hunting partners Merkel 470 Nitro Express. It will do the trick on buff or elephant if you can shoot it well enough. 400 gr cast boolits make great practice loads and shoot to regulation at around 1800 fps. A lot cheaper than practicing with Hornady Dangerous Game solids! Get ready to buy a LARGE press and brass is not cheap either. But hey, it is a 470 after all and they don't sell ammo or components at Wally World for sure!
Now after all that is said, if I was going to Africa tomorrow, I would buy a Ruger 77 Mk II in 375 Ruger and put a long tube 3x Leupold on it and call it good to go. You can darned near buy 11 Rugers for what the Merkel cost. Spend the 9k$ savings on trophy fees and airline tickets.