I have only been in one gunfight but it involved me putting 4 rounds of 45 ACP into a man's torso with no immediate visible effect. I was under whelmed by the legendary stopping power and instant lethality of the mighty 45 ACP.
I used to buy the hype surrounding the 45 ACP. This incident opened my eyes to the truth. No pistol is particularly powerful and nothing is a sure bet to stop a man.
BINGO!
Both 45acp for 100 years, and the 9mm Luger/Parabellum for 105 years, have been competing ON THE BATTLE FIELD for dominance. Neither has been or can be shown to be clearly superior. 100 years of direct combat experience for both, and all we know for sure is that both work. The 9mm has vastly more history and ‘experience’ then the 45acp around the world.
My own combat experience is military, and I have used a 1911 45acp and a S&W Victory model (model 10 ‘K’ frame) 38spl. Handguns, I didn’t see any real difference in results when bullets are placed where they needed to be or when the bullets didn’t go where needed.
My point is that as far as handgun of combat calibers are concerned where the bullet goes is what counts, NOT WHICH CAILBER goes there.
I mostly carry a 1911 because I like how thin it is and still fits my hand very well. When I carry 9mm these days it isn’t my Hipowers, but one of my HK P30’s. because the P30 is the gun that fits my hand best after the 1911 that I have ‘fit’ to my hand.
Which caliber I use doesn’t matter, the 1911 carries enough rounds to accomplish anything I need accomplished with a handgun. Although generally more rounds are better than less. I have never felt under gunned or such with a 357mag/38spl 6shot revolver either.
If I do my job the caliber will work or not as well as any other fighting caliber. I have yet to figure out the reason for the 40 Short & Weak either. Obviously some very experienced folks disagree with me, but in the end it is purely opinion. Not fact.
Pick a reliable platform, Make sure it fits you, and you don’t have to adapt to the gun, and then get all the quality training and quality practice you can afford. Learn your weapon and maintain it properly.
If you think “which caliber is better” is the question, your really don’t understand the problem.
Spend your effort, time, and money learning to make good hits during a real fight. Not rationalizing caliber selection.
Good luck.
Fred