I still like the 22LR, but whatever you currently own with a reasonable supply of ammo will do. Remember, it isn't about going out and buying a gun and ammo when supplies are tight it is all about what you have and what you could scrounge in a SHTF scenario. I would venture all this ammo that is being hoarded isn't being shot up rapidly.....if you had to scrounge in abandoned homes, businesses or on dead bodies for stuff...you would find 22 first off and 9 mm second most plentiful.