There are currently 311,228,791 million people in the United States.
The FBI estimates there are 200,000,000 guns in the United States in the hands of private citizens, and another 120,000.000 in the hands of the police and military. That equals one weapon for every man, woman, and child in the States.
It is however a bit deceptive. The FBI estimates that only one in four people own weapons, but those that do, own four to six weapons.
The next logical step would be to figure out how man bullets are in existence? Its really hard to get this type of data, as there are so many manufacturers as well as people who reload their own brass. Having said that we know that a single vendor, Lake City Ammunition ships over 1 billion small arms rounds a year to the military. So its pretty safe to say there are enough rounds to take out the combined “turned” population of the States.
Of course, that’s only if you have them, and have enough people left to use them when the end comes, but its an interesting bit of knowledge when you think about it.