Well Blitz......
Mr. Brooks suggests the M1 .30 caliber carbine for zombie hunting. Short, lightweight and compact. More than enough power for shooting thru rotted zombie melons. Smaller/lighterweight cartrage means more ammo on board for the same weight size as higher calibers.....made in mass quantities so parts/spares should be easy to come by. Ruger made, not sure if they still do a single action pistol (revolver) that also fired .30, that way your rifle AND pistol would use the same ammo. That way less space would have to be devoted to ammo differentials to keep diffrent caliber systems loaded.
A fine weapon for TEOTWAWKI and zombies
Now if you're looking into some thing for "zombie sniping" i.e., long range hunting......
A savage in .308, hell just about any .308 bolt rifle will fit that bill. If you also wanted a "civilian" .308 assault rifle (semi auto firing) then a springfield M14, G3, CETME, FNFAL would do ya just fine.

-Bill Liptak