The AR7 is a neat little gun, but it has soome issues IMO for a survival tool. First, its a semi auto. It requires a magazine and will not function well with all ammo. (thats not a AR7 issue, its a semi auto issue) It has more breakable and moving parts.
If it were me, I'd very much prefer a bolt action rifle like a Marlin offering. It can shoot any 22LR ammo you scrounge and is not prone to jamming with dirty or out of spec ammo. The down side is size, not much can beat the compact storage of the AR7.
Savage makes a nifty gun, 22LR and shotgun combo... but its heavy.