Elephant Gun or Not, which is the truth?

I saw an outdoor show two weeks ago that had a man kill an elephant with a bow and arrow. The heavy hunting arrow was traveling a good deal less then 300 fps. The elephant went down within sight of the hunter. He shot the elephant just behind the shoulder from about 11 yards away.So I would have to say if you are crazy enough and lucky enough it can be done with most any caliber if it can be done with an arrow and be that effective.