Some of the break barrel airguns shoot pretty fast (1000 FPS) but with only a 10 grain pellet. Compare that to the same velocity .22 LR with a 40 grain projectile, and there is a major difference. However, in the very long term (If I were forced to infinitely live in a survival situation kind of thing), it would be nice to have the pellet gun because you can carry hundreds of pellets easily, compared to .22's. That's because with the .22's, most weight and size comes from the casing, which in an airgun is you... you are providing the power to launch the projectile.
But for what you want, a little combo .410/.22 would be great.
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