I Made an Untraceable AR-15 ‘Ghost Gun’ in My Office—And It Was Easy

(This article originally appeared in WIRED)

This is my ghost gun. To quote the rifleman’s creed, there are many like it, however this one is mine. It’s known as a “ghost gun”—a term popularized by gun control advocates but increasingly adopted by gun lovers too—because it’s an untraceable semiautomatic rifle with no serial number, existing beyond law enforcement’s information and management. And if I really feel an unusually private connection to this deadly, libertarian weapon, it’s because I made it myself, in a back room of WIRED’s downtown San Francisco workplace on a cloudy afternoon.

 

I did this mostly alone. I have nearly no technical understanding of firearms and a Cro-Magnon man’s mastery of power tools. Still, I made a completely metallic, functional, and accurate AR-15. To be particular, I made the rifle’s lower receiver; that’s the body of the gun, the only part that US legislation defines and regulates as a “firearm.” All I needed for my completely legal DIY gunsmithing venture was about six hours, a 12-yr–old’s understanding of pc software program, an $80 chunk of aluminum, and an almost featureless black 1-cubic-foot desktop milling machine known as the Ghost Gunner.

The Ghost Gunner is a $1,500 computer-numerical-controlled (CNC) mill sold by Defense Distributed, the gun access advocacy group that gained notoriety in 2012 and 2013 when it started creating 3D-printed gun components and the Liberator, the world’s first totally 3D printed pistol. While the political controversy surrounding the notion of a deadly plastic weapon that anybody can obtain and print has waxed and waned, Defense Distributed’s DIY gun-making has advanced from plastic to metallic. Like different CNC mills, the Ghost Gunner uses a digital file to carve objects out of aluminum. With the primary shipments of this sold-out machine starting this spring, the group intends to make it vastly simpler for regular folks to manufacture gun elements out of a material that’s practically as sturdy as the stuff utilized in industrially manufactured weapons.

In early May, I obtained a Ghost Gunner, the first of these rare CNC mills loaned to a media outlet, and I tried it out. I’m going to give away the ending: Aside from a single temporary hardware hiccup, it worked remarkably well. In truth, the Ghost Gunner worked so effectively that it might signal a brand new era within the gun control debate, one where the barrier to legally building an untraceable, sturdy, and lethal semiautomatic rifle has reached an unprecedented low level in price and skill.

But the Ghost Gunner represents an evolution of novice gun-making, not a revolution. Home-brew gunsmiths have been making ghost weapons for years, machining lower receivers to legally assemble rifles that fall outside the scope of American firearms laws. In fact, when we revealed the Ghost Gunner’s existence last yr, the feedback section of my story flooded with critics declaring that anybody can do the same garage gunsmithing work with an old-fashioned drill press.

I could hardly judge the fancy new CNC mill in WIRED’s workplace with out attempting that methodology too. Or for that matter, Defense Distributed’s earlier trick, constructing gun components with a 3D printer. Before I realized exactly what I was stepping into, I decided to try all three methods in a ghost-gun-making case study. I would construct an untraceable AR-15 all 3 ways I’ve heard of: utilizing the old school drill press technique, a commercially obtainable 3D printer, and eventually, Defense Distributed’s new gun-making machine.
All the parts of my AR-15, together with my do-it-yourself decrease receiver, the gleaming aluminum piece. Josh Valcarcel/WIRED
The Ingredients of a Ghost Gun

Almost no one builds a ghost gun from scratch, and I didn’t either. The shortest path to constructing an untraceable AR-15 requires only that you build one comparatively simple part your self, a part that’s become the main focus of a fierce gun control controversy: the lower receiver.

US gun laws have centered on the lower receiver because it’s the essential core of a gun: It holds together the stock, the grip, the ammunition magazine, and the upper receiver, which includes the barrel and the chamber where the cartridge is detonated. As Doug Wicklund, senior curator at the NRA museum explained to me, the lower receiver always carried the serial number because it’s the part that remains when the others wear out and are replaced. Like the frame of a bicycle or the motherboard of a pc, it’s the nucleus of the machine around which every thing else is constructed.

My AR-15’s do-it-yourself lower receiver. Josh Valcarcel/WIRED

It’s worth noting that buying an AR-15 within the US isn’t hard. But the privacy-minded—as well as those disqualified from gun purchases by felony records or psychological illness—can make their very own lower receiver and buy all the other parts, which are subject to nearly zero regulation. I ordered each part of my AR-15 but the lower receiver from the web site of Ares Armor, a Southern California gun vendor that doesn’t require any personal data beyond a shipping address. If I wished to cover my purchases from my credit card firm, I could have paid in bitcoin—Ares accepts it.

There’s even a technique to anonymously purchase that highly regulated lower receiver—almost. Like many gun vendors, Ares sells what’s referred to as an “eighty percent lower,” a chunk of aluminum legally deemed to be eighty percent of the way towards becoming a functional lower receiver. Because it lacks just a few holes and a single precisely formed cavity known as the trigger well, it’s not technically a regulated gun part.

Machining the final 20 percent myself with a CNC mill or drill press would enable me to obtain a gun without a serial number, with no background check, and with out a waiting period. I wouldn’t even have to show anyone ID. Law enforcement could be completely unaware of my ghost gun’s existence. And that sort of secrecy appeals to Americans who consider their relationship with their firearms an extremely private affair that the government ought to keep out of.

Controversy swelled around ghost weapons when John Zawahri, an emotionally disturbed 23-yr–old, used one to kill 5 folks in Santa Monica in the summer of 2013. Even so, they haven’t been outlawed; buying or selling a ghost gun is against the law, however making one remains kosher under US gun control laws. California state senator Kevin Deleon launched a bill to ban ghost weapons last year, following the Santa Monica mass shooting. Governor Jerry Brown vetoed it a couple of months later.

But as the shouting match over ghost weapons gets louder, few of the shouters have actually tried to make one. Even fewer have tried to check how the evolution of a new set of digital “maker” tools is altering that gun control question.

So over the course of one unusual week in WIRED’s office, that’s what I set out to do. Here’s the way it all went down.

 

The drill press, jigs and vise I used in my first attempt to finish an eighty percent lower receiver. Josh Valcarcel/WIRED
The Drill Press

Remember when I stated I know nothing about using power tools? Unsurprisingly, this portion of my gunsmithing experiment didn’t go well.

Step one: Acquire a drill press, an enormous stand-alone drill meant to cut the aluminum features out of my eighty percent–lower receiver. One $250 rental charge later, two colleagues helped me haul a drill practically 6 ft tall all the way down to our building’s loading dock, a dark and chilly concrete space occupied by a pair of huge Dumpsters. I’d paid Ares $97 for a set of steel-carbide drill bits and end mills—tools that act like bits but also can cut sideways like a milling machine—all of which the company recommended I use with the drill press to do the job. I paid another $110 for a set of steel jigs, metallic stencils that would guide the machine as I tried to mill and drill exact shapes.

All that planning and spending, it turned out, couldn’t compensate for my utter lack of even high–school–level shop abilities. Before I’d even begun, I realized I had the incorrect sort of vise, and we had to drive an hour and drop $80 to pick up another one. Then there was the drilling itself—which, it would prove, is not as simple as it appears on the Internet.

I reviewed my lower-receiver drilling basics on YouTube one final time, put on latex gloves and eye protection, screwed the steel jigs around my slug of aluminum, tightened the clamps, and hit the chunky green power button.

As the drill bit chewed into the block, I felt a rush of excitement and tasted fine aluminum dust between my teeth. The bit threw off metallic shavings and left behind a gleaming, polished crater. But my elation faded as I realized how badly I was mangling the trigger well. No matter how hard I cinched it down, the vise shuddered continuously, moving the aluminum piece. The holes I was cutting veered off till they were practically diagonal.

When I switched to the end mill to clean up the spaces between the pits I’d created, I discovered they had been mostly at different depths: The drill bit had somehow moved up and down, and I hadn’t noticed. The bottom of the cavity I’d made began to resemble the surface of the moon. Meanwhile, the huge machine protested loudly, shaking like a train about to derail. Throughout this ordeal, WIRED video producer Patrick Farrell, a former bike mechanic who most likely could have offered useful advice, watched me wrestle from behind his digital camera with a restrained smirk. The unwritten rule: I was in this alone.

I kept at it for 5 and a half hours. Then the head of the drill press—the part that holds the bit, which I’d later learn is called the “chuck”—fell off. I had no idea whether this was supposed to happen as a form of fail-safe, or if I had destroyed an costly piece of equipment rented with Farrell’s credit card. I screwed the chuck back in, and after a few more minutes of metal-on-metal violence, it dropped off once more. (I still don’t know if I damaged the drill press, however a gunsmith later explained to me that it likely wasn’t designed to handle the lateral stress of using it as a milling machine.)

That’s when I gave up. I had nothing to show for my labor but a sad metallic block scarred by a maze of crooked channels. Well, that and a left hand bristling with tiny aluminum shards where my latex glove had split.

A 3D printed lower receiver on the print bed of a Makerbot Replicator. Josh Valcarcel/WIRED

 

3D Printing

I left the grease-soaked drill press in WIRED’s loading dock, headed back upstairs, and pulled a $2,800 Makerbot Replicator from its box. It felt like the elevator was a time machine shortcutting about a century of technological progress.

I plugged the 3d printer, followed a series of delightfully idiot-proof instructions, and in minutes was test-printing a tiny white coffee table. Soon I was ready to begin making gun parts; no obscure YouTube instruction videos, calipers, jigs, or aluminum splinters required.

I discovered the blueprint for a printable, reinforced AR-15 lower receiver on The Pirate Bay. It was one of dozens of gun parts out there for download in the rogue BitTorrent repository’s “physicles” section, a part of the site created in 2012 to host controversial digital blueprints other websites wouldn’t or couldn’t. In fact, the file I downloaded had been created by Defense Distributed in 2013, but the group had pulled it from its personal web site after the State Department threatened to prosecute the group’s employees for weapons-export-control violations.

It took a couple of minutes to torrent the lower receiver file. I opened it in Makerbot’s printing software, centered it on the app’s digital representation of the machine’s print bed, and clicked print. The printer’s motors started to whir, and within seconds its print head was laying out extruded white plastic in a flat structure that vaguely resembled the body of a semiautomatic rifle. As the workday ended and WIRED’s office emptied, I found myself sitting alone in a darkening room, transfixed by the gun part slowly materializing before me.

At one point, six hours into the 9-hour print job, the Replicator’s print head overheated and took a while to chill down. That required pressing one more button on the machine. I didn’t touch it again. The next morning I got back to the still–dark room and found a completed, eerily translucent lower receiver glowing inside the Replicator’s LED-lit chamber.

As science-fictional as that process felt, the results were flawed. When I pried the finished lower receiver off the print mattress, one side was covered in support material meant to prevent the hot plastic structures from collapsing before they solidified. Snapping and scraping off that matrix of plastic was a long, messy process. I tried using a knife, cut my thumb, and bled all over one side of the rifle body. And the same support materials also filled tiny holes in the piece, in some cases choking the delicate threads meant to accept metallic screws.

It’s clearly possible, based on YouTube evidence, to 3D-print AR-15 lower receivers which are capable of firing hundreds of rounds. But mine wasn’t so practical; I wouldn’t know it till I visited a gunsmith two days later, but I’d eventually give up on assembling a gun out of that plastic-printed lower receiver long before it was anywhere close to a becoming a functional weapon.

The Ghost Gunner, with an eighty percent lower receiver bolted inside. Josh Valcarcel/WIRED

 

The Ghost Gunner

The new technology of “maker” instruments like 3D printers and CNC mills have been lauded as machines that allow anybody to make anything. But from my first moments using the Ghost Gunner, it was clear: This is a machine designed to make a gun.

Defense Distributed’s CNC mill is a simple black cube, with two tiny stepper motors sticking out of two of its six sides. As if to underscore the power contained in its microwave-sized footprint, the machine was so heavy I could barely lift it from its box. When I did haul it onto a table, I was struck by the lack of branding or the toylike LED lights and buttons of the Replicator. Its stark simplicity mirrors the unmarked gun parts it’s designed to create.

The Ghost Gunner works with either of two pieces of software: GRBL, an open source, general-purpose milling application, and DDCut, a Windows-only gun-milling program created by Defense Distributed and recommended by the group for anyone other than advanced CNC mill users. The Ghost Gunner also comes with the DDCut instruction file for milling an AR-15 lower receiver, shipped on a USB thumb drive in the box. (Putting it on the Internet, as with the 3-D-printable files, might have prompted the State Department to threaten Defense Distributed with prosecution again for weapons-export-control violations.)

I installed DDCut and found that for its primary purpose of finishing a lower receiver, the Ghost Gunner is absurdly easy to use—mostly because I was never given the chance to make any choices. Once DDCut began running the AR-15 file and cutting into my 80 percent-lower receiver, my only interaction with the software was clicking “next” through a 22-step set of instructions and then doing things to the aluminum part that the software told me to do.

For one hour-long stretch in that process, I was given nothing to do but simply admire the Ghost Gunner as its blurred, cylindrical blade cut away the gun’s trigger well with inhuman precision. At other times it seemed to alternate between carving aluminum and assigning me tasks like changing the lower receiver’s position, tightening and loosening bolts, switching the end mill to a drill bit, or even vacuuming up the aluminum shavings that piled up in and around the machine. Eventually, it felt much more like the Ghost Gunner had programmed me to be its gun-making tool than vice versa.

The Ghost Gunner drills out a lower receiver’s trigger pin hole. Josh Valcarcel/WIRED

Over those hours, I couldn’t help but appreciate the beauty of the Ghost Gunner’s design and engineering. As it patiently removed metal, the aluminum piece and the cutting tool moved in robotic, mesmerizing patterns. The noises the machine produced alternated between high-pitched shrieking and low groans that echoed through the WIRED newsroom and elicited complaints from neighbors. But during quieter lulls, the Ghost Gunner also emitted a series of rising and falling harmonics, produced by vibrations of the mill’s stepper motors, that sounded like a kind of alien melody. My editor, Joe Brown, who came into the room to watch the machine at work, remains convinced the machine was programmed to play a piece of composed music.

When it was only three steps away from finishing its full process, however, the Ghost Gunner hit a serious snag. The probe the mill uses to measure the lower receiver’s location malfunctioned, and the machine locked itself. To get it moving again, I had to break the rules of my experiment and call Cody Wilson, Defense Distributed’s founder, to seek advice. At first he told me I’d have to rerun the entire process—close to four hours of wasted time. “It’s a design flaw,” Wilson admitted. “If it stops, it has to start again from the beginning.”

But Wilson soon came up with a better plan and sent me a new file that rehearsed only the last portion of the AR-15 cutting process. Twenty minutes later I pulled from the machine the shining, perfect body of a semiautomatic rifle, as warm as if it were some baked good fresh from the oven.

My fully assembled AR-15. Josh Valcarcel/WIRED

 

Assembly

The Ghost Gunner’s lower receiver looked obviously superior to my 3-D-printed one—and even more obviously superior to the hot mess of uneven aluminum I’d chewed up with the drill press. But before assembling the full weapon, I wanted an expert opinion. So I visited Bay Area Gunsmithing, a sunny garage in Novato, California, populated by two professional gunsmiths, a very impressive collection of ordnance, and a gracefully aging dachshund named Ruth.

When I showed my manually drilled lower receiver to Nathan Rynder, the shop’s owner, he dismissed it immediately. The hammer and trigger wouldn’t fit into the narrow, winding gorge of the trigger well I’d created, and I hadn’t even gotten as far as drilling holes for the selector and trigger pins. (He did note that he’d seen worse attempts, including a customer who had brought him a lower receiver with a gaping, unintended orifice drilled through its side.)

I was more surprised when Rynder insulted my 3-D-printed lower receiver. “This is not ready to rock,” he said, skeptically probing the part’s details with his fingers. He pointed out that the blueprint had misplaced something called a “takedown pin hole,” and he made a further to-do list of necessary fixes before it could be assembled. “You’d need to thread in a pistol grip, clean out the buffer tube threads, clean up everything a pin went through,” Rynder said. “You’d need several hours of labor to clean this thing up.”

Just the idea of a 3-D-printed lower receiver bothered him; if the ring that held on the buffer tube and stock (the big loop at the back of the receiver) were to break, he pointed out, it could unleash a large and powerful spring inches from the shooter’s face. “It scares me,” Rynder said.
My Ghost Gun Budget

Building an untraceable AR-15 with the Ghost Gunner is pricier than it would be with a traditional drill press. But it requires far less skill than that manual method and costs less than creating the gun with a typical 3-D printer.

My Ghost Gunner–milled AR-15 body, by contrast, got a stoic nod of approval. Rynder—who, allow me to stress, makes guns for a living—wasn’t exactly wowed that I’d produced a functional, essentially flawless lower receiver. But he gave me the go-ahead to build it into a full rifle. “It’s safe to assemble, safe to fire,” he said. “Yes, you could put this together and it would be ready to go.”

Over the next hour in Rynder’s shop, I constructed my AR-15. This was harder than Forrest Gump makes it look. But I persisted, learning the process as I went by watching a YouTube video from Ares Armor a few seconds at a time. (At a couple of points, Rynder couldn’t help but point out that I had inserted a part backward or give me an unsolicited hint. I suppose this was cheating in my one-man gunsmithing experiment, but unfortunately Rynder was a very friendly, helpful, and competent person.)

When I finally slotted in the pins to attach the upper receiver—a component that looks much more like a gun than the lower receiver and whose total lack of regulation is, frankly, bizarre—they made a pleasant chink. My AR-15 was complete.

I looked down at the fully built rifle and something in my brain shifted. I realized that the abstracted parts I’d been fiddling with had turned into an object capable of killing someone. My lower receiver had transformed from a “gun” in a legal sense to a “gun” in a very practical sense.

I remembered that I should start being careful where I pointed it.

Firing my AR-15. Josh Valcarcel/WIRED

 

Shooting

Three days later, at a private range in Richmond, California, a half hour from Rynder’s shop, I loaded my AR-15 with a 10-round magazine of .223 caliber ammunition and fired it for the first time. I pulled the trigger hesitantly as I aimed at a piece of cardboard 50 yards away. The deafening blast silenced the tweeting of nearby birds and echoed around the range’s wooden walls as the rifle’s stock dug into my shoulder. I could see a tiny hole in the cardboard. A plume of dust rose from the dirt berm behind it.

“Well, it goes bang,” Rynder said.

I fired again. Then three more times. Then I emptied the magazine. Then I reloaded and emptied another one.

Halfway through the next magazine, I pulled the trigger but got nothing but a soft click. The rangemaster, who happened to be a former winner of the shooting competition reality TV show Top Shot named Chris Cheng, diagnosed that the upper receiver had jammed and needed to be lubricated—a common problem with new rifles. He opened it up and doused the bolt and buffer parts in grease, then put the upper receiver back on.

My rifle performed perfectly for the rest of the morning. After our video team fired the rest of the 40 rounds I’d brought, Rynder walked over to the neighboring range and convinced the friendly local SWAT team members practicing there to give us another 60 rounds. We shot those too. The gun didn’t misfire again.

 

Exorcising My Ghost Gun

The day after that shooting field trip, I had a flight home to New York. Taking my ghost gun on a plane—legally, three ghost guns, in fact, since I had created three lower receivers—seemed unwise. I couldn’t leave them in WIRED’s office in San Francisco either, because that might count as legally transferring ownership of the unserialized guns, which is a felony. I considered destroying them with a hacksaw, but regulations posted online by the Bureau of Alcohol, Tobacco and Firearms seem to demand that a lower receiver be destroyed with a blowtorch, removing enough metal that it can’t possibly be welded back together.

 

So instead I decided to surrender my three lower receivers to the local police. I disassembled my AR-15 and left a large box containing all of the parts except the lower receivers on my editor’s chair. Then I walked down the street to the police station in San Francisco’s SoMa neighborhood and told the lady at the front desk I wanted to hand over some firearm components. She gave me a puzzled look and asked me to sit down.

Forty minutes later, two cops emerged from a door and asked what I was doing there. I explained and showed them the three lower receivers. They examined them with expressions that were simultaneously quizzical and bored. I asked them if it was common to see AR-15 lower receivers like these: homemade, with no serial numbers. “I’ve never seen this before,” one of them said.

The cops gave me a handwritten receipt for the three weapons I’d turned in, as if to definitively present that these were not outside of law enforcement’s awareness or control: They now had a number. Then they took my lower receivers behind their locked door and I said good bye to my ghost gun.

When this story was published, the Ghost Gunner still sat in a storage room of WIRED’s workplace a couple of blocks away. It’s ready to make another lower receiver at any time. And Defense Distributed has already sold more than a thousand of their gun-making boxes, each one a tiny, easy-to-use, anarchic rifle manufacturing unit.

In other words, to paraphrase the rifleman’s creed once more, this ghost gun was mine. But there will likely be many like it.