Yes I have that video. It's a 500 nitro express. I guess I meant that if the brain is hit, it doesn't matter much about what caliber you're using. I suppose if you miss the brain a 700 nitro might not stop him. It just seems that it would be easier to hit the brain with a more manageable caliber. I think it goes back to the old fast moving small caliber bullet, vs slow moving large caliber bullet. Anyone can tell that a fast moving bullet does more damage to flesh than a slow bullet. This can be seen comparing a 30/06 wound to a standard 45/70 wound. I would think that as long as penetration is achieved, the fast moving 375 bullet would do more damage than a slow moving 600, on a brain shot at least. Of course this all would only apply to Buffalo, not elephant.
But since I love big bore guns, I won't go any further. I'm starting to piss myself off defending small bores! lol!