Where do you live? Do you live out in the boonies? Or do you live in a city or a high density neighborhood?
If you live around a lot of people, a bb gun isn't appropriate for a child who is too young to be trusted to not go out and try to shoot something, and can end up hurting someone. Even 10 year olds make stupid judgment calls, and mistakes.
The old Christmas movie with Ralphie is what I think about when I hear about giving kids' bb guns - the Red Rider that his mom would say "You'll shoot your eye out!" Love that movie!
Oh, and we never gave our kids bb guns, in case you're wondering.
Good luck deciding.
Dawn