It's a moot point. AR's arent the problem like y'all seem to think; here's why:
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This is one of my rifles. It's not a AR-15 or even remotely related to one. It shoots 9mm ammo, just like any random handgun you might run across, though it fires those same bullets at a higher velocity thanks to the rifle's increased barrel length. It takes Glock 17 magazines and those can be had from the standard 17 round joints (on the far left and right of the pic), all the way up to a 50 round drum magazine. Mine, are 17, 21, and 27 round. I could easily buy a 33-34 round stick if I wanted to. That would make my ammo capacity on par with the average AR's 30 rounds. Also, I can, and have dumped entire 27 round magazines in far less than a minute. The average AR's rate of fire is about 45 rounds a minute: again, we're about on par with an AR.
The point here? If I load and aim at anyone, the result is precisely the same as an AR: Someone may die and likely will.
AR's ain't the problem; the AR is just popular. There are plenty of rifles out there with similar or close capacities to the AR's standard 30 round magazine. There are some that run ammo that is considerably more powerful than the 223 or 556 rounds an AR uses and those guns are quite popular for hunting and, therefore, are just as easily accessible as an AR15.
Don't get hung up on the whole AR15-thing.