I managed to worm my way into an trip to Africa. There are limits to what I can take, based on the selections already established by the other three hunters who have been there several times. Because of their plans, I can only take one rifle. I'm not complaining, since I'm spending very little to round out their party. Their usual fourth member had to drop out. There is a strong possibility that Cape buffalo will be on the schedule, since it is a 10-day outing. The minimum rifle allowed for that is a 375 H&H or equivalent 375 cartridge. Is that what I should be looking at?
If you intend to get in on the buffalo, that would be the minimum. Of the several rifles available for it, Winchester's Model 70 is as good as any and priced right. Check their website. Personally, in the same position, I would have a meeting with the others to clarify matters. Will you or will you not be hunting Cape buffalo? If so, consider a 416 Remington Magnum, again in the Model 70. Load some 350-grain bullets for smaller game. They'll just punch a hole in light game, and do a fine four-legged drop on those that are sturdier. Even the huge eland has no chance with a properly placed bullet from a 416. You didn't say where you are going, but the lions in some areas can be real pissy. The 416 will also protect you. Carry it with confidence. Adapt to the considerable but not disabling recoil. If you shot almost nothing but Swift A-Frames, life would be good. But, on follow-up shots on buffalo, slam in 400-grain solids, one after the other. The first 400 should be a perfectly placed expanding bullet. If you're going to be taking some long shots, the ballistically excellent Barnes Triple-Shocks in 300 and 350 grains will shoot about as flat as a 30-06. But first, I'd invite the group out to dinner at a nice restaurant and try to get more clarification of what they intend to do, and what they will be expecting from you. Don't tag along if there is not equal respect and consideration, and you would only be going as an expense reducer for them. It isn't worth it; not in Africa.