On paper at least, the .22 Mag rifle has a whole lot going for it as a one-rifle option in a disruption scenario.
Adequate for self-defense out to 125 yards or so.
Adequate for small game out to 150 yards, and for deer out to 50 yards.
I'm sorry, but I don't understand this constant complaint that .22 mag ammo is "very expensive." Compared to what? You can get 50 rounds of quality ammo for around $14 a box. What does a box of fmj M1 carbine go for? And what does a box of M1 carbine soft-point go for?. Lots lots more.
The boxes of 50 of the .22 mag ammo come in small plastic cases, that weigh less than one filled 15 round mag of .30 carbine. You could easily carry 200 to 400 rounds of .22 mag without sweat.
Availability? I see lots and lots of it in every gunstore I ever go into. Far more common and available than M1 carbine rounds.
Now, I'm not trying to trash the M1 carbine. It is a great rifle, with lots of applications, and adequate for self defense out to 200 yards. But, in a disruption scenario, the ability to travel light, move fast, and carry lots of ammuntion would be a key. Not everybody can hump 400 rounds of M1 carbine or other centerfire rounds.
And, though I am not much of a fan at all of the .22 Mag in a revolver (simply because it is deafeningly loud!), I could see that it would be smart to have one on your belt, as a companion to the .22 Mag, to carry in a bad situation, for self-defense, not hunting.
Moreover, though it would be illegal, I can almost hear a President in a martial law scenario ordering the National Guard to take every gune carried by folks, except for .22 rimfires and shotguns. (My understanding it that even in Russia, during the darkest and most oppresive years of communism, folks were always allowed to own a .22 rifle and a side-by-side 12 gauge.)
Just my thoughts.
Regards, Mannyrock