Here we have, essentially the only survival rifle you will ever need!
Its the Chiappa M6 X-Caliber 12 gauge survival shotgun. Its pretty close to being just as compact as the the Henry AR7. Though its the versatile nature of this beast that really makes it shine. The X-Caliber adapter set can fire up to 12 different calibers including the following: .380 , 9 mm , .357Mag/.38SP , .40 S & W, .44 Mag, .45 ACP , .410/.45colt, and 20 gauge. Steel made except for a foam insert that reduces the weight and is inserted in the butt stock. This thing can actually fit in a backpack, just by pressing a lever that folds it. You also have options for scopes, lights and bipods, as theres plenty of rails to attach.
You are looking at a price of just under 800 bucks. Not bad considering it could be your only post apocalyptic survival rifle that youll ever need!