Yes, your friend does not know what he is talking about. I have shot charging buff in the chest with my .450 Rigby, using either 500 or 550 gr bullets at 2370 and 2230 ft/sec respectvely, and it might change their minds, but often does not. If they are attacking, or fleeing over you, they must be killed to stop them reliably. I have turned a buff cow, but she only turned about 15 yards after my shot, so I do not know if it was my shot that took some time to have an effect, or if something just cahnged her mind. I do imagine that I could see a change in her determination after my shot, but that is my very subjective observation. I think what makes elephant dangerous, is that you are far more likely to be charged by an unwounded one. I have had a few charges by elephant, luckily all gave pre- warning, and a hasty retreat/ shot over head was all that was neccicary. so far, I have not have to kill one in self defence, or even seen it happen. A lot of elephant charges are mock charges, and can be handled by facing them, or making a racket (shots fired, yelling). Whould love top hear what Ganyana thinks on this topic...