I agree that a 9mm beats a .22 for a survival pistol. I might even go with 10mm.
If your survival depends on stopping people from harming you, I would agree. Otherwise, not so much.
Just out of curiosity, anyone actually hunted small game with a service pistol?
I find it tough enough with a .22 pistol.
Now, SHOT shells in a service pistol make some sense, but you will have better accuracy, and way more shots for the same bulk of ammo with a .22.
A 9mm+p+ JHP will do a lot, but if its only squirrels about will anything but a head shot be worth it? And can you and a service pistol make that head shot?
2" at 25yds can be a clean miss on a squirrel.
Forget, for a moment, easy to pack, if you are talking about food to live on, a rifle is better than a pistol, unless you are an excellent pistol shot. And a .22 is better because you can have more ammo. You WILL miss. Count on it. PLAN on it.
For most survival situations, you would be better off using trapping skills for small game than hunting them with a gun.
The Combo guns like the Savage 24 are tough to beat for utility. Camp gun, something packed in the plane or the boat, for emergencies, something capable of taking about anything you run across (with the right ammo), until you get found, or walk out, pretty good choice.
So is the USAF survival combo .22/410 (not sure what the current maker calls them), and is even smaller and lighter than the savage.
Maybe, this MIGHT be a useful niche for the .45/410 guns like the Judge. Assuming you accept the drawback of bulky ammo...
SALT might just be a vital thing. How much of a deer are you going to eat before its rotted? Being able to salt and smoke meat might be of great benefit, as well.
A deer gun when there are no deer is so much useless weight. A couple of deer SHELLS for a small game gun is much less burden, and still useful if you get lucky.
A .22 is about the most useful I can think of, particularly when mated with a shotgun. Also think about some flare shells for the shotgun. The old "3 shots in a row = distress" signaling works for searchers ON FOOT. The guys trying to find you from a helicopter won't hear them. Sending up a flare (or tracer?) stands a better chance of being noticed.
However, be prudent, certainly someone will notice the forest fire you might start, but may NOT notice you...also, if you DO burn down the north woods, to signal for help, you will be expected to pay for it.