I take it you have a .22 WMR based on your screen name. Don't underestimate the .22 Mag especially in the Hornady 30gr V-Max bullets going 2200 fps. I have a Ruger 10/22M with a magnum research carbon fiber barrel. I guarantee it would stop or slow down an intruder. Put 10 of those puppies in a zombie and it'll give you an excellent advantage over the undead. Then you can use your scrapyard to finish them off.
This is the ultimate .22 WMR anti zombie gun(Grendel P-30). 30 rounds of pure zombie melon exploding goodness. Super reliable and 10 mags should get you through most scrapes with your brain intact.
Ted Wilson Dum inter homines sumus, colamus humanitatem. BTW - Winter is Coming.