So, what would be your weapon of choice during the Zombie times?
I'd go with a framing hammer. Guns break and run out of ammo. Shotgun shells have a limited shelf life. Swords and knives break and need sharpening. And a crossbow is just ridiculous. (But looks very cool.)
If I did use I gun, I'd choose a .22. Around the south, you can find .22 ammo at every sporting goods store, bait shop, and Walmart. Hell, they sell them at convenience stores.
How about you?