Hows a 9mm JHP work compared to a 9mm FMJ.
Much better. A great 9mm jhp seems to be almost as good as a 45 jhp. But for ball ammo, 45 is way way better.
In my case, Spring of 1977: 4 rounds fired, at about 20 meters, going for headshots, and I got two for certain-I saw bits of scalp fly. The other guy got off two rounds from a sawed-off Universal M1 carbine, one of which passed between my left arm and my chest and burned the inside of the left arm just a bit. His other shot hit me just a bit south of my solar plexus, happily while I was wearing a Second Chance Z9 soft Kevlar vest, fairly new at that time. He droped his carbine and walked away. I considered a magazine dump into him, but was concerned that he might have pals along with him, and had but one full spare mag for the GP- and it had Finnish Lapua ball ammo in it. Thankfully, I didn't need it.
The first cop on the scene was our county sheriff, on whose advise I didn't bother filing a written report...and I got to keep the abandoned carbine out of the deal. About a year later, the guy with the bulletproof head died in a DUI accident [probably- it was a hit and run] on his Harley.
If he'd gotten past me, his next problem would have been my fiancée at the time, waiting for him with my Remington 870 with 8 rounds of Winchester short magnum #1 buckshot in it. She had the better idea.
I mostly carry 1911s in .45 nowadays, though the last serious shooting in which I was involved was a matter regarding a rabid dog about two years back, in which I used a Walther P.38- which has nice, large, very visible sights. The first one broke the dogs back/spine at the hindquarters, and the second one was a mercy shot, unfortunately NOT to the head, since that's the part the state board of health needs intact for post-mortem examination and testing.