AR-15s come under the category of arms. At the time of the writing, there were no automatic firearms. AR-15s are not excluded from ownership by citizens.There's no second amendment right to own an AR-15.
The banning of AR-15s would be just about as effective as the banning of pipe bombs. It would have ABSOLUTELY no effect on terrorists.
The banning of anything only creates a black market for the banned item. We banned alcohol for a while. How did that work out? We banned certain drugs. How did that work out? We have laws against murder. How has that worked out? We have laws against adultery? How has that worked out?
People that think banning certain guns will make everything peaceful in Mayberry are living a non-realistic dream.
The only thing that will stop a rampaging terrorist with a firearm is a well armed LEO or a good citizen with a firearm. Since LEOs are always "just around the corner", I prefer that good citizens carry and use their own weapons and take out the threat when the need arises, not after LEO and the press corp gets there to count the bodies.
Laws banning AR-15s (or magazines for more than 10 rounds) will have absolutely no effect on criminals that want to use them.
Grab this: CRIMINALS DO NOT OBEY LAWS!