Its not just that...there are different variations of the AR that can shoot way more potent calibers of ammo than the 5.56. You have the 308/7.62 Nato, .458 SOCOM, .50 Beowulf and others...and I think its criminal to allow an 18 year old to buy something that can literally shoot someone's head off. The seriously effed up part is that 18 year olds are blocked from buying handguns, but can buy a way more potent rifle...what kind of sense does this make...who is the asshat that lobbied for that stipulation.