You said: In my opinion a key societal objective is to keep people safe...countries having significant gun restrictions have an order of magnitude fewer gun related deaths...you'd be hard pressed to argue that there's no correlation here.
Take a look at Switzerland, where everyone over 18 years old has an automatic rifle (not the semi-automatic AR). It might be a cultural thing, rather than a gun ownership thing. Although even Israel has fewer mass shootings, because the shooter is usually shot after his first couple victims. Granted, if you have an island, or a non-free people, or both, and control of data collection, you can have great gun death statistics.
And, we know that governments have killed many orders of magnitudes more people than individual gun owners. Individual gun ownership keeps governments 'honest' when it comes to things like contemplated genocide. You want to kill 6 million people?...you have to disarm them first. You want to kill 6 million armed people?...you might think about it twice. If you want to count gun related deaths, include those killed by governments who have safely killed because their population was disarmed. Those numbers show it is safer to live in a society with armed citizens.
BTW, I know a little bit about guns...while I don't own one, as a teenage I ran a rifle range at a Boy Scouts summer camp...was responsible for ensuring all the younger scouts knew how to handle the gun, clean it and, of course shoot accurately. Later, I shot a military sidearm, BAR and even manned a 5"-38, but that doesn't count...or does it? As Justice Scalia said..."The Second Amendment is NOT unlimited (my emphasis)"...you can't own a piece of artillery and the government has every right to restrict other weapons as well (e.g. AR-15s).
Have you ever fired an AR?
The AR, by the way, is just a platform, invented by ArmaLite (the "ArmaLite Rifle"). It is merely type of semi-automatic loading and firing system which is currently used by all kinds of guns in all kinds of calibers. Hundreds of manufacturers use it. Some make AR platform 12 gauge shotguns. Some make AR platform .22LR (.22 long rifle) rifles. You name the caliber, and there are dozens to hundreds of guns using the AR platform to shoot it. The AR lower can accept non-conforming uppers, so you can even buy an AR bolt action, and an AR crossbow (seriously). That's why it is the most popular rifle in America. It is the most versatile, and easy to use firearms platform.
And, AR's don't have to be the dangerous black color that liberals seem to hate so much. You can even get wood stocks for them, so that they look more like what liberals think a gun should look like.
And the caliber the guy used in Colorado was a standard small game (varmint) hunting round.
So, what are you going to ban? There is no way to do it without banning all semiautomatic rifles.
You describe what you want to ban, I will educate you on why your idea won't work. Seriously...give it a shot.
But aside from your inevitable failure in banning guns, the mere effort to try such a ban (assuming you would try to confiscate firearms) would be destructive beyond belief. (If you are only talking about a ban of future sales, nothing will happen, because it won't work.) Confiscation would cost far more lives than are currently being taken on our streets today. I assure you, if you were to try to remove guns from the United States, that would be the end of the United States. That's not a threat from me; that is just an observation....because my goal would be to sit it out, in my recliner, while it all goes down. I'll be watching the revolution on TV with a whiskey in my hand, cursing the people who were naive and stupid enough to think they could get away with a nationwide gun ban. If you thought January 6 was bad (a day in which they all left their guns at home), just try to take guns away from Americans. I can't imagine a more well meaning policy that would have worse effects. And if there is anything I learned on January 6, it is that there are a lot of people out there who get far more upset, far sooner, about things that don't even motivate me to get off the couch. You think those types of people will sit back and disarm? It is silly to even talk about a US gun ban. Even Chris94 knows this. No use closing the barn door after the animals have all escaped.
And what do we "get" from owning those AR-15s that tips the balance of safety and sanity in that direction?
You get a government that fears oppressing its people too much. You're welcome.
Or, if not that, then at least a government that feels it needs to treat the people like a frog in a pot on the stove...turn up the heat and hope they don't notice the increasing water temperature. But, guess what...the frog always jumps out.
There are 4 boxes of freedom, to be used in order of priority and frequency: (1) the soap box (free speech), (2) the voting box, (3) the jury box, and (4) the cartridge box (used only as a last resort, like our Founding Fathers, but the prospect has a deterrent effect). This ain't about blowing up water melons, or any other recreation...although if that is all they get from those weapons, then that means things are going very well in our society. Oh, and by the way automatic weapons are so rare and so restricted, they are very rarely used in killings...I want to say maybe single digits since WWII?
Allowing access to weapons - especially those designed for military use...
"designed for military use"...that undermines your argument.
Many rifles were designed for military use. Take, for example, the Henry Lever action rifle which was standard issue to the US military for years.
But, interestingly, the AR was specifically designed not for military use, and in fact has never been used by the military for that very reason. It was specifically designed for civilian, non-military use. You might want to try a different argument.