I have been using my 375 H&H, 416 Ruger, and 450/400 3 inch on past trips. This coming trip will be PG only and no eland, so 7 RemMag and 50 cal. White muzzleloader.
Just like NA shot placement is more imp than calibre, within reason. Also use good quaility controlled expanding bullets.
I have use a 7mmR. mag on PG, 400-800lbs, with 175 gr. Swift A-frames with excellent results. With heart/lung or high shoulder shots rarely recover a bullet. Animals go straight down (high shoulder shot) or go 40-100 yds and fall over dead.
My guns were lost by delta air lines on my last trip so everything I killed was with a .270. As for my wife she shot her kudu, nyala, leopard, etc with either a .308 or .222
I shot my eland with a .270 and it was still more gun than needed. If I had my guns with me I would have been shooting a 338 lapua mag as always. Next time I go back I'm hunting cape buffalo and I'm gonna take a break over .243 just for giggles.
I laugh every time I get off the plane and see all those guys carrying their old doubles with outdated ballistics etc. Wonder if most of those guys know that a 45/70 has less energy than most rifles our kids shoot now a days. and they hunt buff with em!
I've shot African game with the following calibers:
257 Roberts, 270 Win, 30.06, 300 Win Mag, 375H+H, .416 Rigby
375 H+H is the minimum required for Dangerous game in most countries. Plains game is often hunted with standard US deer rifles. The 30.06 is well respected and accounts for much game in Africa each year, just like in the US. There is no need to get hung up on rifle calibers for most hunting in Africa. A rifle you shoot well and comfortably is the most important issue. You will likely be shooting a lot more than you typically would in the US on a hunt. Leave the big bores and ultramagnums at home unless you are after DG. I love my Rigby for ele and buff, but it just isn't the best choice for most plains game hunting.
YD: In 40 years of flying Delta, I have never missed or lost a bag. In my experience, their gun handling has been above average. If given the choice between one hour and four hours between flights, tho, I always allow plenty of transfer time. Just cautious that way-I've always been a belt AND suspenders kind ofguy!