Although I don't shoot for a living and haven't had plenty of experience, I must say I have seen a few mock charges from Ele and even Lion but have only had to shoot one in self defense.
The distance was at about the maximum legal distance for a self defense shooting which was about ten yards but in this circumstance we had no choice than to shoot to kill as it came straight for us from about twenty yards from a standing position through super thick cover bolling over trees on the way.
If it was in more open country we might have been able to let it come in a couple more meters but know doubt with the same outcome.