How many guns are regestered in the US?

This question continues to come up, with great regularity. In most U.S. states, there is no registration, regardless of what anybody tells you. "Register you gun" is something people say because they have heard it on TV. There are 3 or 4 states that require registration, but the other 46 or 47 states do not, and there is no federal registration. So, in the vast majority of the U.S. there is no such thing as registration.