In context, survival in Alaska, a Combo 20ga/.22mag like the Savage 24, the Rossie Bronco, The Bak and even the Springfield M4 in .410/22 mag. You can pack a chamber exchange piece in like 20 ga to 30-30 for single shot use and they are light weight enough to carry it and 10 rounds. I would not want a complecated piece, one that can break such as a pump or semi-auto. Plus a single shot will promote ammo conservancy.
I do agree with Huntsman though that most small game is easier had via snares, traps, but OPTIONS is what will help you survive... so your ability to create snares/traps along with your ability to shoot if need be is where I would be at mentally for a survival situation.
So..... My vote
20ga/22mag with 20 mixed rounds of 20ga and 100 rounds of 22mag, chamber reducer in either 30-30 or .308 and 10 - 20 rounds of that ammo. We are talking survival.... not a 25 year base camp.
I have actually tested various scenarios with diff pieces and in the end, my lil folding Savage mod 24 in 20ga/.22mag with the chamber reducer in 30-30 is my way to go in almost any survival situation.
In the survival kit in my sons aircraft we take to all kinds of places is a Springfield M4 in .410/.22lr with a small mix of ammo in the pack, we use the same small pack for the canoe trips and pack horse trips when we go fly fishing in Montana.
We both have diff levels of survival pieces though... we will have a rifle with us, then in the pack, the survival piece and on us 24/7 we both carry a American Derringer .410 with a small mix of ammo for it. But the one thing we do is make sure all the pieces we have will at least interchange the ammo we have with so the .410 and 22 can be used in the rifle/pistol and survival piece interchanble save the chamber reduced piece and rounds.
Regards,
Mike