Hi bruinruin,
I've never mentioned flesh wound predictability. I was thinking along the lines of penetration of practical media.
I am not sure of inferential predicability of water as a test medium.
A good idea might be to buy an intact car door from a junk yard, take it to a suitable location, and fire rounds through it. I have also seen photos of wounds, both of survivors and those on pathologists' tables. Handguns are not best for saving one's life, but they are most practical. Handgun stopping power is a gun magazine myth. It might not be wise to rely upon a myth.
For handguns to work at their optimum, deep penetration is crucial. In fact, I'd prefer through-and-through wounds. If the CNS ain't hit, you gotta get the bad guy's blood pressure to zero posthaste. And if a bad guy is on myth or PCP, just about everything we know is out the window. I know of a cop who shot a bad guy 6 times in his chest with the ultimate man stopper, a .357 Mag. The bad guy was trying to rack a police shotgun. Six .357 Mag rounds to his chest didn't cause him to flinch. However, when my friend fired one 870 round to the bad guy's chest, he became property of the coroner.
I have witnessed many penetration tests, including cars as media. But for non-law enforcement, shooting through cars assuredly has little application. However, one might have to shoot through a refrigerator.
In the very rare occasions when I carry a handgun for self-defense, it's loaded with heavy-for-caliber bullets; e.g., 180 grain LE .40 S&W rounds. A bullet performs a lot better if it penetrates, and heavy-for-caliber bullets usually penetrate deepest. And I don't like frangible bullets. I like, heavy, well-constructed bullets that remain intact with as close to 100% weight retention as possible. I use lighter bullets for only target practice.
