Will people like these circumvent the law and mill out their own 80-percent receivers? There are always exceptions, but generally no. Education and personality factors create a threshold not everyone can cross.

If you’re a regular person, it’s not difficult to build an AR-15. If you’re an outlier, beset by a mental health issues that warp your perception of reality, it’s probably not going to work out for you.

Back at my desk, I took the finished lower and set about making it into a functional weapon. I installed the trigger, safety selector and other parts inside the newly-milled pocket.

To my mild surprise, everything fit. The safety selector, in particular, has a gritty feel to it. But it works.

A quick confession—my new firearm isn’t technically an AR-15, but an AR-10. This variant is similar except that it fires a more powerful 7.62-millimeter NATO bullet, compared to the standard AR-15’s 5.56-millimeter round.

I built a semi-automatic rifle in my kitchen. I’ll bet that’s one sentence you’d never thought you’d hear. Neither did I, until the day I decided to do it.

The job required drilling aluminum, and tiny shards and slivers of metal were going to fly everywhere. It’s not something you want to do over carpet, so I decided to do it in my kitchen.

Did it work? Hell yes, it did. After three hours of work with light tools, I had built the essential component of an AR-15 rifle. America has now reached a point where people can construct modern weapons in their kitchens.

Is this awesome, crazy—or both?

In my extended group of friends, seven of us own AR-15-type rifles. Perhaps not coincidentally, we each bought one after turning 40.

Buying this kind of rifle is the modern version of getting a Corvette during your mid-life crisis—but cheaper and probably less dangerous.

There’s a subculture—and cottage industry to support it—around AR-15 rifles. After adding accessories to my first rifle, swapping out parts and purchasing tools, I realized I had a knack for it.

I was an AR-15 grease monkey. During the course of several projects, I’d built an entire rifle from scratch. But I’d never built the lower receiver of an AR-15. By U.S. government standards, I’d be manufacturing a firearm.

The Last 20 Percent:

The Bureau of Alcohol, Tobacco and Firearms controls the sale of AR-15 lower receivers. As far as the law is concerned, the lower receiver is the weapon. It’s one of the few parts you absolutely need to make a functioning firearm, and they’re usually stamped with a serial number.

AR-15 enthusiasts who build their rifles at home must go to a gun store to buy a complete lower receiver. They undergo a federal background check, and other state laws—such as a 10-day waiting period—may apply.

But there’s a way to dispense with the background check and other state laws—and that’s a so-called “80-percent” lower receiver. This is a lower receiver with only four-fifths of the aluminum finishing done. You do the rest yourself.

The ATF recognizes the right of Americans to build their own firearms. It also recognizes that a lower receiver, only 80-percent finished, is technically not a firearm and thus not subject to regulation.

Anyone can go online and order an unfinished lower receiver for delivery to his or her home. All you need to finish it is a router, hand drill, vise and drill bits. Patience, a willingness to follow directions and more patience are also essential.

Once you’ve completed the remaining 20 percent of the machining, you’ve got yourself what the ATF considers a firearm. You don’t have to register it, do a background check or add a serial number. You can now buy the rest of the rifle off the shelf and build it yourself.

The idea of completing the circle by building my own AR-15 lower was something I couldn’t get out of my head. The zen aspect—like completing a bonsai tree by trimming away everything that wasn’t the tree—held particular appeal.

Trial and Error: 

My first stop was a company in Santa Ana, California that makes 80-percent lower receivers. I bought the receiver, a jig—which showed me what to mill—and a drill bit kit.

To round out my supplies, I ordered a router—the kind that builds furniture—from Amazon. I would use my own electric drill.

I assembled the vise in my kitchen and went to work. This would be my first time working with metal. First, I drilled six holes into the top of the lower receiver. As I drilled into the receiver’s 6061 aluminum body, tiny pieces of metal piled up on the floor.

Starting now, I was across the legal Rubicon. Once I’d drilled out the tiniest bit of aluminum from the lower, this hunk of metal legally became, according to the ATF, an “other” firearm.

After I drilled out the holes, I turned to the router. Using an end mill, I slowly connected the freshly-drilled holes, forming a pocket where I’d later insert the trigger and safety.

It was delicate work. Trying to mill out too much aluminum at once risked shattering the end mill. Go slow and it cuts aluminum like butter. Go too fast and you can, as I learned the hard way, shatter an end mill.

Three hours of work later, the job was done. The milled pocket exposed raw aluminum—and the result wasn’t pretty. My first complete lower looked like a monkey made it with a Dremel tool.

But the mess was on the inside of the rifle, and once I had installed the proper parts, nobody was going to notice.

Isn’t This Dangerous?: 

Should people be concerned that you can make a gun with a 30-round magazine in your own home, completely undetected by the government?

Theoretically, yes. Just like theoretically, it’s not a good idea to let people own cars that drive 200 miles per hour.

The reality is that Americans use AR-15s and their assorted variants in a surprisingly small number of gun crimes. In 2013, the latest year for which the FBI has statistics, 12,253 people were murdered in America. Of those, handgun deaths comprised 5,782.

Total long gun deaths, covering everything from hunting rifles to AR-15s, comprised 285. By comparison, in 2011 Americans killed 428 of their fellow citizens with blunt objects, such as clubs and hammers.

AR-15s may seem like an ideal weapon for criminals, but most of them are more than 30 inches long, making them really, really hard to hide. A criminal has to conceal a gun before—and often after—committing a crime. It’s no coincidence that handguns outnumber rifles 20 to one in gun-related homicides.

Still, not everyone needs to be discreet. Some, like mass shooters, just want to kill a lot of people.

Will people like these circumvent the law and mill out their own 80-percent receivers? There are always exceptions, but generally no. Education and personality factors create a threshold not everyone can cross.

If you’re a regular person, it’s not difficult to build an AR-15. If you’re an outlier, beset by a mental health issues that warp your perception of reality, it’s probably not going to work out for you.

Back at my desk, I took the finished lower and set about making it into a functional weapon. I installed the trigger, safety selector and other parts inside the newly-milled pocket.

To my mild surprise, everything fit. The safety selector, in particular, has a gritty feel to it. But it works.

A quick confession—my new firearm isn’t technically an AR-15, but an AR-10. This variant is similar except that it fires a more powerful 7.62-millimeter NATO bullet, compared to the standard AR-15’s 5.56-millimeter round.

I haven’t turned it into a full-fledged rifle, yet. I didn’t build the lower receiver just so I could add a weapon to my collection.

I did it because I could.

This was first published by WarIsBoring here.

Image Credit: Creative Commons.