There is no set age limit. This is best decided by the Parent and child. If an educated parent feels it is the right time for the child to learn good safety gun handling then I encourage that they take the time to teach or have someone teach the child how to handle the BB gun. It's all about education and safety.
The age that I think is right for a child to have a BB gun is 10, because they would have seen enough gun accidents so they will know (hopefully) what not to do and what to do.
Depends on your parents and the police.
Your parents will decide.
21
It all depends on the law where you live.
18 to purchase
If its a BB Gun, Then Yes.
You need to take this question up with the child's parents.
18 years old
You must be 18 Years old to purchase one
Depends on your skills, size and parents.
No
It's up to your parents
You have to be 18 to purchase a BB gun but you can use one under adult supervision or guidance at any age as long as you act mature and understand the basic safety rules of handling a BB gun or Rifle