Ideas = Things

For those of you who don't know what this is, let me explain. The image is a 3D model of the lower receiver of an AR-15 rifle.

In the USA, a firearm generally has one critical part that is considered the controlled item. This is the part that is, legally, a "gun." It has the serial number on it. All of the other parts are just that - parts, and are available to pretty much anyone.

If you have that controlled part, then you can buy the rest and build your firearm.

For the AR-15 rifle, that controlled part is the lower receiver. It is the part that hold the magazine, and contains the trigger and fire control parts. The upper receiver holds the barrel and pins to the lower receiver. You can order a complete upper receiver with a simple internet search and a credit card. You an buy one cash-and-carry from a retail store. The same goes for the parts and bits that go into the lower receiver.

One unique aspect of the AR-15 design is that the lower receiver actually doesn't have to deal with a lot of stress. It just holds things together. Though it is usually made of aluminum, there are commercially available ones made of tough composite plastics.

What makes this particular 3D model significant is that it appears on the "Thingiverse" site where people exchange such files for use on their 3D printers. Combine that with the fact that 3D printers are rapidly coming down in price, and today anyone who can afford a computer and is willing to hack a bit to get something working can have a 3D printer. While this design might be a little challenging for the home-units, it won't be for long.

It has always been legal in the USA for an individual to construct a firearm for personal use. A license is needed to transfer that a firearm that you made to another person, but not to make one. There are (onerous) restrictions against making full-auto weapons, silencers, and a few other things. In general, though, you can legally build pretty much anything you can purchase across the counter at a sporting goods store.

This hasn't been a real issue because making things like this is generally difficult, and requires specialized tools and skill. At least it did.

With 3D printing technology, you download the file, and press "Print."

The line has been crossed between possessing mere information and being able to easily turn that information into "things."

While an AR-15 with a lower receiver made from extruded ABS plastic is not likely to be as rugged as one machined from an aluminum forging, I have no doubt that it could be made to work.

In the Soviet Union, photocopiers and printing presses were dangerous things. They had to be licensed, registered, and were heavily regulated. Somehow, ideas spread anyway.

Now the same level of technology can make things, not just spread ideas.

hmmmm...

P.S. - the difference between an AR-15 lower receiver and its selective-fire military cousin is a slightly different internal geometry and another hole.