The AK is a good backup weapon, but I preferred the hunting rifle. One shot kills, sometimes more than one zombie per shot if they were single file.
Once you get the semi-auto Barret .50 cal it's all over. Most of the zombies didn't even get halfway to my barricade, even the runners.
The game is too easy, though. If I didn't repair my barricade at all through the entire game it wouldn't have gotten under 85%.
I'm an uzi guy.
I want that hour of my life back.