The easy answer is that we already have and leave it at that.

In thinking on this more, a great choice was made by Eleanor O'Connor.

A 7x57 covers 99% of need
A .30/06 was her big rifle which she used up to Elephant using 220gn FMJ's, but the OP states NA as the hunting perimeter, so again, Eleanor may have it right.

When truth is ignored, it does not change an untruth from remaining a lie.