hoppdoc,

This is all an exercise in mental gymnastics, in my honest opinion.
Having said that, and in regard to your friends formula, several buddies of mine and myself started to compile the volumes of traumatized tissue from various calibers with recovered bullets. What we found is that there is a descent correlation between bullet velocity, frontal area, and the speed of sound in the the tissue medium. Now granted we made some rather sweeping assumptions with regard to the speed of sound in the tissue medium. The reason one must consider the speed of sound and the frontal area (and shape, but that tended to be rather consistent bullet to bullet with regard to soft points) is the hydrodynamic effect of the bullet on the tissue itself. Anyway, enough mental gymnastics.

Real world stopping power. Well I can tell you from first hand experience if you shoot a bison in the head with a 300 Win mag and miss the brain it doesn't really do anything (okay it bleeds a bit), lets call that a stopping power of 0. If you shoot a buffalo or bison in the head with a 500 Jeffery and miss the brain they typically fall down, and take a few seconds (only one I had this happen to that didn't die took about 20 seconds to get back up) and it wasn't feelin' too good when it did ie no more walking, running, let alone chargin'. I have actually killed a few with missed brain shots (two to date) both expired from broken necks, believe it or not, again shot with a 500 Jeffery improved. The 416 and 375 I have seen only two from the former and one from the latter and neither was able to drop a buffalo or really impress them too aweful much with a missed brain shot. By the way, brain shots ain't as easy to make as many seem to think!

Buffalo can run a good many yards with absolutely NO heart (something in the area of 30 to 50 yards for sure I have seen it myself). The 500 Jeffery Improved with a 570 gr Woodleigh at ~ 2400 fps will literally explode the heart, and leave a wound channel of ~ 6" to7" in diameter with an exit hole around 3" to 4" (rib cage now not hide). The buffalo can still run far enough to stomp your arse. By the way, in my experience buffalo typically won't consider charging unless you are inside ~ 30 yards. The closer you get to them the higher the liklihood of a charge. At these ranges they can easily get to you even with a shattered heart and a shattered front leg.

The truth simply is the only RELIABLE charge stopper is a CNS hit. The real big bores (500 and up) do seem to provide some margin for error in that they will knock down an animal with near brain misses (and in my actual experience can actually kill). The lesser calibers do not seem to provide this little extra insurance.

That is all I have to say about that.

Scott