When anyone talks about a "last ditch revolver", I conjur up scenes of a broken civilization, with every man(person) for themselves. A lot of factors go into that scenario, things like personal defense, survival (game taking), home defense and so forth. Some of the things that affect the decision are:
1. Simplicity-things should be as simple as possible, its obvious.
2. Ammunition availability, having a .44 magnum is not good if the only available ammo is 22LR.
3. Quanities available.
4. Ammo/weapon effectiveness for defense/game taking.
5. Portability, it may be probable that you might have to hump everything you own long distances.
I would assume that you are going to start out packing everything you need, that might let out a lot of large bore guns. The .38/.357 folks are not far off, but I would go just a little smaller. The .327 mag/.32 mag is quite light and packable, as are the revolvers made for it. It can be a formidable defense round, and also take small game easily without blowing it apart. The ammo is light, and a very large quanity can be carried compared to other bigger rounds.
In extremis, I might even favor trhe .22LR, it will probably be then as now the most available round, and one can carry a lot of it, and one should not sneer at a properly place .22LR.
Sometimes, when folks plan for "the day", I wonder what will they do with their massive quanities of weapons/ammo, if they have to leave their homes and flee somewhere. On can carry only so much, I plan to go by bicycle if necessary, obviously my second choice, but there a lot of reasons why a motor vehicle may not work, or will only work as far as the fuel in the tank.
Think about it.
