Hollow points are designed to penetrate sufficiently at the right velocity but then fan out to prevent overpenetration (in theory) and produce cavitation. With all the +P++++ and such everybody uses nowadays, not so sure they're gonna stop in a human. Most humans aren't too thick. I have rarely seen FMJ perform as well as HP for real target shooting either, assuming a person is good enough to measure their accuracy to this level. HPs are all around higher performing bullets, but they also have a higher price. HPs shouldn't jam up a good semi (Glock, Sig, Beretta, S&W M&P, etc, etc).