You will need to define assault rifle, and where you live. A TRUE assault rifle is a machine gun, and transfers of them are tightly regulated by the Federal government. What most people CALL an assault rifle is nothing but a semi-automatic rifle, and in most of the US, does not require a license to possess.
No.
No.
Have never heard of an underwater assault rifle. In the US, you must be 18 to buy a rifle, and 21 to buy a fully automatic rifle.
No.
18 to buy a rifle or shotgun, 21 to buy a handgun or assault rifle.
No.
You can buy a semi automatic Title I rifle at 18. To purchase a true, select fire (auto or burst) NFA tax stamped assault rifle, you must be 21.
are you asking if you need a drivers licence? walmart sells them but I believe you have to be 16 or18 to buy them
A TRUE Assault Rifle is fully automatic. Federal law requires you be 21 to buy one of those in ANY state. However, what people may CALL an assault rifle (such as a semi-auto AK47) can be purchased at 18.
You will need SOME kind of LEGAL and VERIFIABLE identification to buy a firearm from a licensed FFL dealer.
You must be 18 to buy a rifle. The stock has nothing to do with it.
18 for a military style semi automatic. For a true assault rifle, which would be an NFA Class III full auto weapon, 21.