What age can a kid have a BB gun?

It depends. I've seen BB guns you can buy at sporting goods stores, but you have to be 18 to purchase one unless a legal guardian or parent buys it with or for you. If you mean to have one, like, to own, it depends on your age. BB Guns are not real guns, but they are still guns that fire metal pellets. Airsoft fires plastic, but BB fires metal. So, no matter what, they still ARE a weapon. If you are under 18, ask your parents or legal guardians because there really isn't a specified age, but I wouldn't let my kid have a BB gun until he was at least 13. Airsoft guns are a whole different story. Since you have this information, decide for yourself.