"...maybe buying a milsurp " battle " rifle or an AR before they are banned..."

If you want an AR, fine, go buy one. I love shooting the AR series, and would love to have one, but can't justify the cost, plus my home is in CA, and they have taken all the fun out of buying a "black rifle" anyway. BUT, if you are worried about being nuked by North Korea, or a PHRASECENSOREDPOSTERSHOULDKNOWBETTER., what are you going to shoot at, the inbound missle? I think your money would more wisely be spent on an emergency generator or something like that. Good for a varitey of uses, perhaps the least of all emergency lighting or running your refer. You say that you have "...couple of firearms and about 500 rounds of ammo...", that should be more than enough for anything. We may be nuked, we may be blown up by a terrorist bomb, but I really doubt that we will be invaded by an army...

As for the food, etc, everyone should have several weeks worth of food and water on hand at all times, just in case...