I think people some people would love a zombie apocalypse the same way they'd love a really violent video game... It's basically a legal way for you to release all of the anger and violence pent up inside humans, that we couldn't do in our everyday world without being arrested or killed.
If I were at a gun store, I'd stock up on an M-16 and grab all the ammo in the store, go hold out in a walmart, set up a barricade, and wait for either the army or the food to run out.
Grab as much ammo as i can for my shotgun,my AK and my .45 and get out of there i dont like to stay in one place too long. Also i love zombie killing because Zombies represent everything thats wrong with humanity...there dumb, violent, and greedy....
This reminds me of a story i heard not to long ago. I man walks in to a gun shop and tries to rob it. The police say that they recoverd 12 diffrent cal. bulets from the mans body. To answer the Question just kill the thing.
I'd distract the zombie hoard by flapping my arms and singing "Sheena Is A Punk Rocker" while the people who knew how to use the guns grabbed them up and (hopefully) started shooting. Then I'd moonwalk my ass outta there. I'm thinking this could actually work.