I know that I wrote a bit about Stopping here, but I didn't really discuss ballistics too much. I am too much of pragmatist to really care to much about the science, since the science really isn't very good. You can shoot gelatin, pig carcasses, or whatever 'human body simulator' you like but there are simply too many variables in real world encounters to get accurate data.

Accurate data is pretty important when you are trying to say that some new bullet design has better performance than what you are currently using. Better performance from the users perspective would mean that it was capable of producing fight stopping, physically incapacitating wounds in human targets under normal shooting conditions. It is pretty hard to define 'normal shooting conditions' and it is impossible to determine the actual wounding without shooting a lot of people with them. Instead what we get are metrics about depth of penetration and percentage of expansion against ballistic gel.

Ballistic gel is a pig thigh simulator - it doesn't model human tissue and bones. Humans are made of different kinds of tissue, some of it is more elastic than others. The heart and lungs are designed to expand and contract, where as other organs such as the brain do not. The more elastic tissues are not disrupted or damaged as much as the inelastic tissues by low-velocity rounds.

Expansion is essentially a way of cheating to get a larger caliber. The easiest way to get 100% expansion is to shoot a bullet that is twice the diameter, otherwise it is anyones guess as to how big the bullet will get before it stops. Making a bigger hole is helpful, but making a deeper hole (penetration) is what we really want.

As a shooter all you can do is apply the fundamentals and get your hits. The bullet does what the bullet does, and it doesn't always live up to the advertisers claims. The performance is going to be equal out whatever handgun you are shooting out of assuming roughly the same length of barrel. If an extra inch of barrel gets you another 100ft/sec that is nice but is probably not going to improve the performance of the bullet in any realistic way.

I do carry hollow points (there is no reason not to) but I don't agonize about it. Caliber, bullet design, and weight are largely matters of 'belief' rather than objective science. I care more about my ammo cycling flawlessly than special magic it is supposed to do to the target. I am not really of fan of guns much smaller than .380, and I don't own anything bigger than .45 ACP. The time and effort put forth evangelizing a caliber or a brand of ammunition would pay bigger dividends if it was devoted to dry-fire practice.