Well, a little followup. Some friends went asian buffalo hunting. The guy paying used a .510 Linebaugh Maximum on a SCI sized asian buffalo, at 40 yards. He pulled the shot, and, the bullet went 5-6 feet, down the side, between the ribcage, and skin. Now we have VERY pissed off 1600 pound buffalo. Bullet was 525 grain cast, at over 1350, same stuff I shoot in my Max, all the time.
Back up rifle was also the shooters, who insisted upon using a lever action, .50 Alaskan. Bullet was 500 grains, at about 1700 fps. Hit slightly behind the heart, going through both lungs, since the bull was now moving, NOTHING. NO REACTION, except to keep on running.
The bull was later tracked, and finished, but, it took quite awhile.
The backup shooter originally brought a double barreled 450 nitro express 2, which, with 500 grain bullets, at 2150 fps, has a steady record of knocking the stuffings out of buffalo and bison, knocking them off their feet, enough to make the second barrel a finishing brain shot.
After much discussion with the principals, I'm rebarreling my CZ 550 to 416 Rigby, since I agree with Rich that that's REALLY the best place to start with buffalo rounds...
S