In Capstick's book he talks of the early elephant hunters using black powder 4 bore's. It would knock them off their horses, break their shoulder and was so bad on the stocks they would wrap the stock in wet elephant hides to reinforce them when they dried. I believe they shot a 4 ounce lead slug.
I believe in the same book he talks of Mr Bell getting a double charge of black powder once causing bodily harm which was the main reason for using the 7x57 on jumbo.