No, no. Bacterial infection.
There are more than just zombies that can kill you.
Lots of guns are illegal to be sold to civilians, like machine guns for instance.
Let's be realistic, if a biological outbreak were to occur I highly doubt the zombies would shamble towards you. They'd run.
Like I said, guns aren't light. If you're carrying ".357 pistol, shotgun, flamethrower, and a crowbar", that's nearly 60 or 70 pounds.