There is a legal age for drinking, for smoking, for voting, for marriage, for driving, for contracts.....and the age for owning firearms should be 21.
(You're a piece of work. You really shouldn't have guns.)
By the way...I believe in the 2nd Amendment. I believe you should be allowed to carry, concealed or not, anywhere you want. Further, I believe we should be allowed to have any firearm and ammo that the govt has. BUT, only after you've reached your 21st birthday.
But no weakling diaper-wearing would-be tyrant like you would dare to come and get them, and that's what matters.