This is a great video that deserves some attention; a data compilation and analysis of real-world handgun shootings. It examines their effectiveness when weighed against other pistol calibers, and against rifles and shotguns.
Here is a comparison I did with two types of expanding/deforming x39 ammo. Both rounds were fired through an M70 Century Yugo AK with a 16.25″ barrel. The test medium was a pair of water-soaked phone books (see “Phone Book