TP-82, a triple barreled double 28gauge over a single 5.45x39. A drilling like the poster above suggested. Fierling configurations might be a good choice also if one could keep it light enough.
Neither of these official survival weapons are for defending against squadrons of Chinese paratroopers, thats just not what survival weapons are for. They arent even particularly useful for when the buggers swarm out of town to cause problems for those of us who live prebugged. You might be able to take out a patrol of 2 but nothing more.
And the added bonus of the detachable butt stock being a machete