I would go with something along the lines of an M1 Carbine, and if I had access to it, a morningstar or kukri at melee distance.
For distance, you want a solid weapon with accuracy and range on your side, you don't want to waste ammo either, hence the semi-auto carbine. For me though, the battle comes down to melee range, you only have so much ammo. The morningstar is a powerful weapon for zombies because of its smashing power and spiked portions, the kukri on the other hand, focus all of its kinetic energy into the slicing due in part to its uniquely shaped blade, thus allowing it to go through limbs much more effectively, the only problem with it is that it is a dagger and thus has a very sort range. Other options I would consider would be a tomahawk (only really reliable when aimed at the head) or a halberd (possibly too awkward to use).