He tested it by shooting several elephants in the head? Where does he legally get elephants to shoot?

Is this like an April fools kind of joke, to laugh at the idiots that are stupid enough to fall for the idea that a totally flat nosed bullet would penetrate better than a sharp pointy one?

I suppose it's not totally implausible though. For example, many people don't realize that a rounded blunt nose object cuts through the air more easily than a sharp pointy object, as long as it stays somewhat under the speed of sound. That fighter jets have sharp pointy noses reinforces peoples erroneous intuition on this point. Of course people don't think of the fact that the speed of sound is an issue for such high speed jets. Indeed slower jets often have blunt rounded noses. And the issue is further confused by the fact that slower aircraft often have pointy noses just to make them look faster, even though it ironically slows them down slightly.

He's copying the nose of a Russian high-speed ("supercavitating") rocket torpedo. The idea behind the torpedo is, I suppose, that its blunt tip surrounded by a sharp edge gives a clearly-defined point for flow to separate at. Without a clearly-defined point for the water flow to separate from the surface of the torpedo, the separation point would fluctuate randomly, giving rise to unbalanced forces. In his water tests, bullets with this special nose shape tumbled more slowly than normal rounded bullets, showing that the forces on their tip were more balanced. But while that is fine for shooting water, any target that is worth shooting in anger or for sport is going to be asymmetrical enough that he's probably wasting his time.