Me personally, for different reasons or under different circumstances, I have at one time or another carried 5-6 shot revolvers in 22 WMR to 357, 6-8 round .380s, 7 to 15 round 9mms, and 7 round 45 ACPs. Life is full of compromises, and sometimes you have to make choices and roll the dice.
Three things:
1. Trust nobody, including me, do your own research.
2.Statistics do not always tell the whole story, and they are based on quality and availability of data used. If the available data only has one person shot with a 44 mag and that person goes down on the first shot, then it is 100% effective. If there are 100 people shot with a 9mm and 95/100 go down in one shot, it is only 95% effective.
3. A creative statistician can bend data to say pretty much what he wants it to say given enough data points
Info:
- .380 ACP, 95 grain: 190 ft-lbs.
- .38 special, 158 grain: 200 ft-lbs.
- .38 Special +P, 125 grain: 248 ft-lbs.
- 9x19mm, 124 grain: 345 ft-lbs.
- 9x19mm +P, 124 grain: 410 ft-lbs.
- .40 S&W, 165 grain: 476 ft-lbs.
- .44 Special, 200 grain: 360 ft-lbs.
- .45 ACP, 230 grain: 369 ft-lbs.
- .45 ACP +P, 185 grain: 534 ft-lbs.
- 10mm Auto, 200 grain: 537 ft-lbs.
- .357 Magnum, 125 grain: 583 ft-lbs.
- .41 Magnum, 210 grain: 705 ft-lbs.
- .44 Magnum (reduced load), 210 grain: 729 ft-lbs.
One shot stops: expanding bullets
- .380 ACP: 68 – 70%
- 9mm: 88 – 91%
- .40 S&W: 90 – 94%
- .45 ACP: 88 – 96%
One stop shots FMJ
- 380 ACP: 55%
- 9mm: 70%
- .40 S&W: 71%
- .45 ACP: 62%
Source: https://skyaboveus.com/hunting-shooting/Defensive-Handgun-Cartridges-are-all-the-Same-Facts-vs-Hype
I don't have an answer to your question, only you can decide if it is enough or not, and regardless of what I or anyone else says on the internet, you have to make up your own mind and you get to live or die with those choices.
What I get out of the above
Nothing is 100% one shot stop, so, practice double taps (more may be needed)
Caliber is less important than being able to hit what you shoot at, under stress, or, failing that, shooting multiple times in the right area (center mass) and hope you hit something that stops the threat.
Hollow points are better statistically than FMJs, but, neither is a 100% one shot stopper.
The energy difference between a 38 and 380 is negligible ~10 foot lbs of force
+P makes a difference in energy level by caliber - 38+p is more energy than 38 special etc. My experience is it also produces greater recoil and slower second shots
The difference between a 9mm and a 45 ACP is pretty much negligible.~25 ft lbs - weight can be a factor here in carrying and controlling recoil - the polymer 9mm is lighter to carry than a steel 1911
10mm is close to 357 in energy
41 through 44 Magnum are higher energy
Dave