All automatic weapons are already illegal in the US and have been for decades. So called Assault Rifles are not automatic, they just look scary.
@ledboots , I am
posting again the article I have shared earlier about how you can - completely legal, for US$ 299 - make your store-bought AR-15 shoot 900 rounds per minute with "bump fire", although
technically not being a "machine gun" (which is why it is legal, although the only difference of this gun to a machine gun is that the shooter has less control over the weapon).
I guess you have not read that article and not seen the video embedded. (Or you have seen it, but continue to say that if it is
technically not a machine gun, then it is not automatic, although you can empty the 30-round clip in 2-3 seconds)
And I agree, The video of the guy firing that gun looks pretty scary to me....
BTW, it is also still possible to legally buy an AR-15 that was converted to full automatic fire (not the same you can buy in the store now) before the 1986 ban on automatic weapons, all you need is a lot more money (US$ 10,000 as opposed to 699+299 for the new one that is not
technically fully automatic), as not so many of these had been converted at that time and they are sought after by fans.