Guns aren't my thing. But it's not that hard to find things out if you're curious enough.
Over the past week, pages of comments have been written about how there's already a ban on fully-automatic weapons, and that the AR-15 is only a semi-automatic. As if that makes a big difference.
Gun folks know these terms easily, and can bandy them about as easily as I can tell you the difference between a Davis airfoil and a NACA laminar-flow wing. But for those of us that might have never even handled a gun in our lives, those terms are as mysterious as medical terminology.
There's two things going on here. What people think of as an "Assault Rifle" is more of a design thing and has little to do with the rate of fire. The real difference is in the firing mechanism. A "Fully Automatic" weapon will fire continuously when you pull the trigger until the mechanism jams or it runs out of ammunition. Some of these have a selective-fire mode, which means you can fire one round, three, or empty the clip with one pull, depending on how it's set. A "Semi-Automatic" weapon fires one round with one pull, but then it clears the chamber and automatically loads another round, so all you need to do is pull the trigger again to fire.
That's it. That's all it comes down to.
"Assault Rifles" as we think of them, didn't exist until very late in WWII. There's more to them than my simple explanation, but essentially it's a portable machine gun. Machine Guns are big, heavy contraptions, and used to be too big and heavy to be easily portable in combat. The revelation was taking the technology and making it portable, while maintaining the rate-of-fire, accuracy, and killing power of large, land-based guns.
But in a crowded nightclub, it makes little difference. Take a look at the video below. It's a professional shooter demonstrating the benefits of a particular trigger type for a gun company. If you look very closely at his trigger finger, you can see it moving, despite what your ears are telling you.
In the interest of fairness, here's a US Military M-16 on fully automatic, fired by a civilian.