A .22 Mag;
30 gr (1.9 g) HP 2,200 ft/s (670 m/s) 322 ft·lbf (437 J)
40 gr (2.6 g) JHP 1,910 ft/s (580 m/s) 324 ft·lbf (439 J)
50 gr (3.2 g) JHP 1,650 ft/s (500 m/s) 300 ft·lbf (410 J)
A .380 ACP;
90 gr (5.8 g) JHP 1,000 ft/s (300 m/s) 200 ft·lbf (270 J)
95 gr (6.2 g) FMJ 980 ft/s (300 m/s) 203 ft·lbf (275 J)
A .22 Mag;
30 gr (1.9 g) HP 2,200 ft/s (670 m/s) 322 ft·lbf (437 J)
40 gr (2.6 g) JHP 1,910 ft/s (580 m/s) 324 ft·lbf (439 J)
50 gr (3.2 g) JHP 1,650 ft/s (500 m/s) 300 ft·lbf (410 J)
)
the 22 mag Critical Defense is one nasty round.
But, for comfort, a 380 would be best just because the gun itself has a smaller grip. I don't think the PMR 30s are to comfortable and unless you want to carry a revolver it rules out a 22 mag for self protection (if that's your intent, I kind of assumed because you mentioned stopping power).
But, between the 2, I'd trust a 22 mag more.
A .22 Mag;
30 gr (1.9 g) HP 2,200 ft/s (670 m/s) 322 ft·lbf (437 J)
40 gr (2.6 g) JHP 1,910 ft/s (580 m/s) 324 ft·lbf (439 J)
50 gr (3.2 g) JHP 1,650 ft/s (500 m/s) 300 ft·lbf (410 J)
A .380 ACP;
90 gr (5.8 g) JHP 1,000 ft/s (300 m/s) 200 ft·lbf (270 J)
95 gr (6.2 g) FMJ 980 ft/s (300 m/s) 203 ft·lbf (275 J)
A .22 Mag;
30 gr (1.9 g) HP 2,200 ft/s (670 m/s) 322 ft·lbf (437 J)
40 gr (2.6 g) JHP 1,910 ft/s (580 m/s) 324 ft·lbf (439 J)
50 gr (3.2 g) JHP 1,650 ft/s (500 m/s) 300 ft·lbf (410 J)
A .380 ACP;
90 gr (5.8 g) JHP 1,000 ft/s (300 m/s) 200 ft·lbf (270 J)
95 gr (6.2 g) FMJ 980 ft/s (300 m/s) 203 ft·lbf (275 J)
I believe the most critical variable is shot placement and that is much more important to stopping a threat than the caliber. Years ago, my wife stopped 3 burglars with a single shot from a Ruger 10/22. One got hit in the shoulder area and sat on the floor bleeding. The other two ran like scared rabbits and were caught by the police within a matter of minutes. One even knocked himself unconscious tripping over something in the front yard.
From your example above, it would seem the most critical variable is having a firearm. Indeed, the shot placement in your example was the shoulder; nowhere near a COM or CNS hit and, yet, the shot had its desired effect.
Research has shown that a significant number of criminal encounters are ended when the intended victim displays a firearm. With this data, and your example above, a strong case can be argued that a 22lr is quite sufficient to stop an attack. Quite frankly, it would be true based on the encounter you described. While I wouldn't recommend people arm themselves with a firearm in 22lr (only if nothing else was an option), I would recommend that people arm themselves with the largest caliber with which they are comfortable shooting well.