I have in several posts cited to the Hall and Patrick text "In defense of Self and others", 3rd edition. While mostly targeted to a LE audience, there are many principals that will translate to civilian self-defense. If you have not bought a copy and read it (repeatedly), you are wrong, and need to overcome your shortcomings in the manner of R. Lee Ermey.

Chapter 4 has a good discussion of ballistics and performance on offenders. Simplified takeaway: the differences between most pistol rounds are not all that great, and generally they are not as good as we would like, even after the decades of research since the 1986 FBI shootout. If you have the ability to predict a violent confrontation, make arrangements to be elsewhere. Elective hangnail surgery is a better choice. If you can't be elsewhere and aren't taking a real fighting rifle or shotgun, you are not very smart.

I am not a cop anymore, so I don't have to hunt for or engage bad guys. That is true of most of us. Don't buy/carry a pistol because they work for someone else. Buy/carry/train with one that works for you in terms of ergonomics, recoil control, and shooting proficiency under all foreseeable circumstances, and that you will ALWAYS carry when lawful.

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NHI, 10-8.