Colorado,

Energy means jack shit in and of itself. A light for calibre bullet can have the energy but not the weight (or constuction) for penetration. A fast projectile that doesn't get there is no hope and a slower but heavier one that doesn't have the velocity (or consrtuction) to get there can be equally useless. Energy doesn't kill, penetration kills. Bell didn't get away with his light calibre elephant hunting because of the energy of the rounds he was using but because of the high bullet weight, ie high sectional density, of the bullets in the rounds he was using.

Nitrox,

Maybe the 45/70 has the penetration for an elephant, and maybe not. Remember that the 458, in those midd'lin years, still at speeds several hunderd FPS in excess of what the 45/70 is remotely capable of, was thought to be issuficient for reliable use on elephant.

JPK