Zombie Defense

Well to answer ken, for normal suburban zombie removal, I like the 20 gauge with #2 or #3 buck. However if your hip deep in Zombies, this link kinda lays it out.
If you simply want to know the best defense load, go out and buy: 12 gauge 2 3/4" shell 00 buckshot. You shall live happily ever after, as this is the most effective man-stopping firearm cartridge yet devised by man. ... One of these rounds is virtually equal to a nine-round burst from a submachine gun, with every round hitting.
I can't argue with your idea of the Tommy, however the full auto ones are out of my price range. :-( If it ever does get to that point I will probably give the 20 to the wife and I'd take the Krag. (The kids get the sks's) I know I can hit just about anything I can see with the Krag. It's better to get them when they are as far away as possible and even the most hungry Zombie can't argue with a 280 grain projectile. I'd probably also strap the 12 on my back, backed up with the pistol, the saber and last but not least the Kbar... after that I'm toast. I guess you fight with what you have. However, I would love to get my hands on some of these babies.