The full-auto switch has been a topic of discussion for quite some time, and yes, the problem is getting worse. I'm still not sure the alarmism is warranted--most firearms recovered don't have them and they're not something you can just slap on any firearm, after all--but they are popping up a lot more than they used to.

This is despite the National Firearms Act, passed in 1934, heavily restricting such devices and the Reagan Era machine gun ban effectively prohibiting them.

The fact that they're popping up on the streets more and more are proof that gun control isn't working. Machine guns were the one area where it seemed that it did, and that is all out the window now.

So what does one op-ed propose? Magazine restrictions.

While gun violence declined last year, a closer look at the data reveals a striking and surprising trend. While the total number of shootings is going down, the lethality of shootings — the odds of someone dying in a shooting — seems to be going up. If that trend holds, it could have massive consequences for gun violence in America, with hundreds or thousands more homicides per year.

A few years ago at a Chicago police station, one of us saw why this is happening. Officers who had stopped teenagers in a car dropped on a desk what they had found during that stop: a semi-automatic pistol with a giant drum magazine appended to the bottom, which would allow the user to fire 100 rounds before reloading. That kind of alteration seems to be more common across the country and is leading to shootings becoming more deadly.

We can see the tragedies that result from data from Chicago over the past 13 years.

...

Glock switches are post-market devices that convert these guns into automatic firearms; that is, anyone with $50 and an internet connection can turn a regular semi-automatic firearm into a machine gun. While these were unheard of in 2010, last year, Chicago police seized 447 guns modified to fire fully automatically. From a public safety perspective, it’s not ideal for someone to be able to fire 100 rounds without having to reload; it’s even less ideal for those 100 rounds to be fired at a machine gun rate.

There's just one problem: Magazines can be printed on a 3D printer as well.

Oh, they might not have the durability of a more traditionally manufactured magazine--I honestly don't know if they do or not, I'm just allowing for the possibility--but they can be made and if they can be made, someone will make them. You can ban them all you want, but the genie is out of the bottle. You're not putting it back in.

See, the authors' issue here is that full-auto switches are a thing, can be made with a 3D printer, which means you're not going to get rid of them. This is a true and accurate statement.

Where they lose the plot is in failing to understand that this applies to magazines as well. You can't just ban what they're terming as high-capacity magazines and make them vanish, especially when people can make them at home now.

The NFA has failed to keep the switches off the streets, as we can tell by the increasing number of them in criminal hands, so we're now supposed to pass another law that can be circumvented via the exact same technology?

I believe the proper word for this is "bat-guano stupid."