Banning the AR15 would be a shallow "feel good" measure and nothing more.
Contrary to what many would have you believe, the AR15 is NOT a military rifle. The AR15 is a semi-automatic rifle that can accurately be described as a "military style" rifle, but no semi-automatic AR15 has ever been used by any military. It is indeed a very good choice for a self-defense weapon and it is also popular for hunting and target-practice. Naturally, it would be a top choice for nutcases who perpetrate mass shootings, but banning it would be little more than a cosmetic measure and would not stop such shootings. BTW, contrary to what many gun-haters believe the initials AR do not stand for "assault rifle" or "automatic rifle" - they stand for Armalite, the AR15's first manufacturer.
If the AR15 were banned, then mass shooters who wished the most effective weapon would simply move on to other semi-automatic rifles, of which there are many. If ALL semi-automatic rifles were banned then shooters would move on to the best single shot rifles or pistols (and pistols have actually been used in the vast majority of gun deaths as well as the majority of mass shootings). Actually semi-automatic rifles were banned from 1994 to 2004. The ban was lifted after intensive study found that the ban had no effect on reducing gun deaths. On the plus side, the ban did cost several gun opponents their seats in Congress.
Banning any kind of guns will only keep such guns out of the hands of law-abiding citizens. Criminals and nutcases are not going to obey gun bans anymore than criminals obey drug bans or other laws. Do drug laws keep drugs out of our schools? Neither will gun laws keep guns out of schools unless those schools are hardened and protected. As the saying goes, "It takes a good person with a gun to stop a bad person with a gun". Plus metal detectors, automatic locking doors, bulletproof glass, etc. Such is the sad shape and reality of our world today. Wasn't that way 30 plus years ago. Despite guns aplenty, students had fights and grudges, but no one reached for a gun or came back to school to shoot up students and teachers. Instead of blaming guns we should blame how society and schools have changed.
We took God out of schools, and we also took civility and discipline out of schools. Much the same as we took such things out of families and neighborhoods- along with nurturing, good parenting and positive male role models. Meanwhile, we added in a culture that embraces violence in our films, our music, our video games and social media. And we added in psychotropic drugs, a common thread in just about all mass shootings. Before you start taking guns away, look at correcting and taking those things away!
If the AR15 were banned it might give reason for a few high fives, or satifsfied clucks, at Starbucks and in the left coast bubbles, but it would do nothing to stem shootings. Once we start down the slippery slope of gun bans, you can bet that bans on other rifles and other guns would become the target. If you don't think so, then you are dreaming. Just look at the laughably absurd memes on social media showing muskets and captioned "This is what guns looked like when the Second Amendment was passed". Yep, that is indeed what the people's guns looked like. It is also what the government's guns looked like
One more time people: Our founders never intended that the citizens should be outgunned by a government that might turn tyrannical. Like the government of King George, who wanted to take our guns away, when we won our freedom. Like the governments of tyrants around the world who have rounded up and killed hundreds of millions of their citizens after they did take their guns away.
As intended by our founders and upheld by the Supreme Court, we the people have a right to strong self-defense weapons. That includes semi-automatic rifles and it includes the AR15.
My two cents.