The .22 LR is a game getter. Have you ever shot a rabbit with a .308? Not to smart, if you plan to eat it. You'll get more animals with a .22 LR carbine than any other gun. And, it won't cost that much either. Plus, if you are on foot, you can carry more gun and ammo, if it's a .22. And, besides, it's dumb to think you're going to be able to take on an army of zombies with an AR anyway. The best strategy will most likely be to hide, escape and evade more than anything else. So, it's obvious that a .22 LR is the best choice - isn't it?