I'm far from an expert on the killing of a Bison having only taken 2. 40/65 win on one and a 45/70 on the other, both with cast. But I've seen "a few" others taken with a 270 and '06. A number of ranches that raise Bison for hunting suggest and/or recommend you shoot the Bison in the head near the ear. The reason for this is that you don't get but 50# of meat, along with the head and hide in your hunt and the rest is sold. Obviously they don't want to throw out a bunch of blood shot meat. (I by the way did not hunt this type of hunt) I've made this analogy before, but here goes again albeit a bit different.......
No one would argue, well maybe some, that a 7mm Rem ultra mag is adequate for Bison, yet a 7/08 is marginal if not down right unethical. But when the projectile leaves the barrel it is nothing more than a 284 dia. bullet. A 7mm in the heart/lungs on a bison at 100yds from a 7/08 is just as dead as one from a ultra at 400yds. You boys looking for an altercation, please by all means start throwing paper ballistics around, be advised I'm not listening. ( leaving for a 2 week job tommarrow and won't be around, LOL)
As far as putting the American Bison in the dangerous game category, I'm not, and I've read the stories too. Most Bison In my humble experience are usually shot at 100yds +/-, unless of course your using archery tackle or a revolver. One more minor point I'd like to make. Again this is from my humble experience as opposed to opinion. Believe it or not there are a few Dangerous Game outfitters in the U.S. (and that does not stand for Africa) that would rather have you bring your underpowered, well worn, can hit a flies ass at 100yds, '06 with appropriate bullets, than to run out and buy the latest thing the gun hacks are getting paid to write about and get a few free hunts out of that you just might not be able to shoot so very well. Have fun Boys...CRASH87