Sadly.....
You're still a "a little bittle kid" in the eyes of the law even though you likely have some fluff on your top lip now.
Also a point to consider - if you live in your dads house, you need to live by his rules, he may have his own prejudices against it regardless to the legalities.
Take him to a skirmish for the day, bit of bonding, you never know he may get the bug and then you'll have all the guns you want.