Hi again Travis2282,
Not being a variable power scope person, I type the following with some fear and trembling in my fingers:
Since you mentioned that you like to use plenty of magnification when deer hunting, it sounds to me that you might be best served by a 2 to 7x variable or 3 to 9x variable for your .375, because 4x is plenty for most African game hunting conditions in general, but especially for buffalo hunting.
Variable scopes work great for those who are not easily distracted.
But, for goofy dudes like me, I have tried same and experienced failure (mine, not the scope).
More than once, when I was young here in The Sates, I had forgotten to turn my scope down so it would focus up close, then some critter leaped from cover and back into cover at close range, before I could find it and put a crosswire on a vital spot.
I'm better off with a simple fixed power scope.
My favorite PH has at least one rifle with only iron sights on it (.458) but also a couple (.30-06 and 7x57) with 3 to 9x scopes on them (he prefers the standard Zeiss Conquest model, in 3 to 9x)
Now when I borrow his plains game rifles, I just leave the scope on 4x, because that is about as good of a compromise for close range and longer range that I can think of, within reason.
A scope is definitely a good investment for a buffalo rifle because sometimes you cannot see clearly any fine sticks between you and the animal without a scope.
Even a very thin/feeble twig can throw a powerful/heavy bullet three feet or more off target, not to mention that it can also cause a bullet to tumble and impact sideways or even backwards.
I have only take one buffalo (shown in my avatar here) and it was with iron sights but my best guess is that a 6x scope might be too much for some buffalo hunting conditions (for some plains game situations as well, such as bush pig, nyala, bushbuck, etc).
Cheers,
Velo Dog.