Gee, thought provoking I guess, but my experience indicates that you get used to what you wish to. I moved from a 30.06 to a 9.3x62 then a 375H&H, finally enjoying the 458 Win Mag and now my favourite 500 Jeffrey. In each instance, the BGRC competitions helped tremendously.

Strongly suggest all of them, irrespective of class is eminently usable, you've just got to have the desire to make it work.

In the field, on buffalo and the like, bigger is definately better, assuming you can shoot the rifle properly. A 500 Jeff on buffalo makes a 375 seem laughable. The 500 really does "numb" them.

If you intent hunting these bigger beasties it may pay to learn how to handle the bigger bores, they certainly make a difference. Not sure they "kill" any better, but certainly seem to "stop" the big beasties with much authority.

As always though, nothing beats good marksmanship, therefore use what you shoot best (within reason ofcourse)