Just do what makes YOU happy. I enlisted at 17 and it took alot of bugging my parents to sign the parental consent but they couldnt be more proud of me now. Just try to ease their mind about it, and tell them its what you want to do, if it is what you want to do, and stick to your guns. Best of luck to you.
Looking for : Savage 24 .30-30/12 Ga
Marlin 336 .35 Rem