Ask your guidewhat to bring most buffalo hunts aren't much more than a glorified canned hunt!!! very few are shot out in the wilds so to speak...........most are hunted on ranches with one purpose and that is buffalo hunting!! the "guides" take ya right to the the animals!!!
I would recomend a rifle in the 30.06 range as most shots are or will be100yds or so!!!!

Let the HuRaaa begin!!!!!