I've resisted answering this question as the premise is faulty. There is no evidence that the "assault weapons" ban has any rational basis. But I happened to read an article that gives a particularly good illustration of the point. Here are two firearm images. The subject of one was banned from 1994 to 2004. One was not.
Can you tell which is which? There are two differences between these firearms.
- The banned one has a flash suppressor. A flash suppressor causes the gun to produce less light and smoke.
- The banned one also has a bayonet lug. This allows one to fix a bayonet to the rifle. A bayonet may block firing (albeit not in this case) and always makes the rifle more unwieldy by moving the center of mass further out. As such, a bayonet would typically make the weapon less dangerous in a mass shooting situation, as it makes the weapon heavier and harder to aim. It would only be more dangerous if the shooter managed to run out of bullets.
Both use the same ammunition and have the same firing characteristics. In case the link dies, here's the answer:
The top one was banned.
Other items involved include the pistol grip. A pistol grip makes it easier for a shooter to hold the weapon while standing even as it makes it harder to aim. The problem is that the pistol grip (which still appears in the unbanned weapon) is one of the parts that actually can be made by a 3D printer. So any criminal shooter can obtain one relatively easily before a planned crime. But someone who keeps a weapon for self defense, would have to break the law continually in order to be prepared for an incident that may never occur.
The real point of these restrictions is not that they keep "dangerous" weapons away from criminals. The weapons that comply with these restrictions are just as dangerous. What they really do is harass gun owners who like to have weapons that look like military weapons. Since this is a minority of all gun owners, these restrictions are reasonably popular when described partisanly. But these are especially profitable weapons for firearm manufacturers precisely because they are a niche market.
Many owners of an AR-15 also own other weapons. These are the kind of firearms that are collected. And collectors will pay extra for something as useless as a bayonet lug.
You might ask why I characterize a bayonet lug as useless when military weapons have them. Military weapons operate in an entirely different situation. An army soldier may be packing not just a rifle and a knife (bayonet), but an entire set of gear:
- Shelter (tent, sleeping bag).
- Gas mask.
A mass shooter doesn't need to carry any of that. If he (mass shooters are overwhelmingly male) wanted that stuff, he'd store it in his car or leave it at home. For the military person, sticking a bayonet onto the end of a rifle makes a crude spear without having to actually carry a spear. But the mass shooter doesn't have to do that. He can just carry an actual spear if he wants. Because he isn't lugging a full pack around with him and can afford to carry a spear.
Of course, your typical mass shooter doesn't do that. Instead, he carries extra ammunition, which he mostly doesn't use. So he never gets into the situation where a spear would be useful, whether single purpose or a rifle-mounted bayonet.