GD, my thoughts on this are:
1. A weapon or weapons almost anyone can "handle" in relation to kick/recoil.
2. A weapon or weapons that is lighter weight than a lot of 12gauge shotguns.
3. A weapon that will allow for the carrying of more ammo per weight than a 12 gauge.
4. In a survival situation MOST of the game taken will be of the small/middle size, from squirrels and rabbits up to possible antelope or small deer (as in younger, not yet so afraid of man therefore easier to "stalk"). Remember we're talking survival here, not sportsmanship.
5. Sound. The .410 is not as loud as a 12gauge, thereby decreasing the possibility of being detected.
It is my belief that the king of the survival weapons might well be a suppressed 22 rimfire semi automatic rifle. You can kill anything up to and including deer with it and it would be very quite compared to even the .410.
Just some random rambling thoughts from me for you to think on.
And with that, it's time for me to hit the sack. Gotta ride the radio for another week starting tonight. Y'all have a good remainder of the day. Stay safe, be happy and don't be afraid to help someone out that needs a helping hand.