Where I live (Canada) you can get your unrestricted firearms license at the age of 18. Unrestricted classifies as most guns used to hunt (ex. shotguns, rifles). You can get a restricted license which allows you to purchase handguns. This is for Canada though so the laws where you live are probably different if you live in the US. Try researching your local laws on firearm possession and purchasing.
if by bbgun you mean airsoft gun then you should be 18. but i am 14 and i own an airsoft gun and play at a local field as long as someone can show the place your buying the gun from an id card (i.e. your parent) you can get the gun.
If by rubber you mean plastic, then 18 is how old you have to be technically. The rule of being 18 to use airsoft guns though is more of a suggestion as most fields will let people much younger than 18 play. It is also not to hard to get airsoft guns online if you are not yet 18 just get a parent who is willing to get one for you.
To buy the gun you have to be 18
21
Your parents will decide.
18 to purchase
It all depends on the law where you live.
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
No
Depends on your skills, size and parents.
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