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Frequently Asked Questions

What kind of 80% receiver do I need?

As shipped, Ghost Gunner can machine any mil-spec AR-15 or DPMS 308 lower receiver with a pre-milled rear take down well. We recommend the lower receivers we sell here.  We cannot currently recommend anodized lowers.

How much does the Ghost Gunner cost?

The total cost of the machine, including the deposit, is $1500.

What end mills does Ghost Gunner use?

Ghost Gunner uses industry standard ER-11 collets, and ships with both 1/4" and 5/32" collets. Changing end mills is a simple process and full instructions are included.

How is the work piece held on the table?

Injection-molded jigs are used to hold the part in place as each milling step is performed. For example, milling an 80% AR-15 lower receiver requires 2 jig pieces to secure the lower in place while the trigger pocket is milled, and then two more jig pieces are installed to drill the trigger pin holes. As most 80% firearms require deep pocket milling, Ghost Gunner's mounting table is parallel to the end mill shaft. This orientation maximizes fixture strength, minimizes complexity, and mechanically aligns the part to the machine upon insertion into the MakerSlide-patterned, open source T-slot stainless rails.

Does Ghost Gunner do engraving?

Yes, GG can be programmed to engrave with popular softwares. For GG-compatible engraving services we recommend W Inceptions.

What is included with my Ghost Gunner?

Ghost Gunner CNC, 6’ USB A-B cable, 6’ NEMA 5-15/IEC C13 three prong power cable, DD USB drive, 17mm wrench, 12mm wrench, 4mm ER11 collet (4 mm ~= 5/32”), 1/4” ER11 collet, 1/4” V31620S end mill, 5/32” 3.125”OAL drill., 3mm ball-end allen wrench, ER11 collet nut, Grip bolt, M4 T slot nuts (x3).

What else do I need to buy for the machine to work?

No additional parts are required to manufacture any compatible AR lower receiver. Just plug Ghost Gunner into your computer, install our software and download any compatible .dd design file (See minimum system requirements here). You'll need to provide the lower receiver and all other firearm parts, including the lower build kit, stock and complete upper. These parts are not regulated for sale in the United States and you can have them delivered to your door without an FFL.

What Open Source parts did Ghost Gunner design?

The entire machine is open source. For other open source designs, Ghost Gunner developed a custom spindle that exceeds the quality, accuracy, and cutting capabilities of any sub-$400 spindle. GG also developed a custom signal conditioning PCB called GrbIO that reduces RF noise generated by the several stepper motors used on the machine. GrbIO includes screw-posts for easy wiring, including separate analog, digital, power supply and chassis grounds, which internally isolate noisy components from sensitive ground planes. The plug-and-play PCB connects between existing Arduino boards, requires zero software changes, and should resolve many headaches on other derivative designs.

How fast can the machine run?

When cutting aluminum, there's little reason to cut as fast as possible. For example, many machines that claim to cut aluminum do so by cutting as fast as possible at depths of just 0.001", which results in poor part tolerance, as only the tip of the end mill actually cuts the metal. The result is the end mill tip dulls quickly and then part quality suffers. Ghost Gunner is designed to cut deep grooves and thus doesn't require a nonsense feed rate to overcome inadequate design. To directly answer the question, Ghost Gunner can run fast (80ipm), but doesn't need to, as it's rigid enough to cut like a real CNC.

Do I need a special power supply?

No. Ghost Gunner uses a standard IEC power cord and is compatible with any 110/220V circuit. No external power brick is used; the machine is entirely self contained.

How do I connect to Ghost Gunner?

Ghost Gunner has two ports: Power (IEC standard) and USB (Type 'B').

What sort of maintenance is required for Ghost Gunner?

Ghost Gunner's moving parts are entirely sealed from chip debris. All bearings are sealed and contain wipers to prevent foreign contaminate entry. The rails are stainless steel and are factory lubricated, but do require periodic wiping to prolong life. End Mills dull over time and are considered a consumable. With proper use, end mills should manufacture dozens of lowers. Emptying the chip tray after each build will prevent chip overflow (shaved aluminum chips occupy approximately 15 times their solid volume). We also offer technical support at

Is manufacturing a firearm legal?

In general, yes. Semi-automatic firearms, including the AR-15 lower receivers, are generally legal to manufacture for private individuals under federal law. However, some states/municipalities restrict either the manufacture of certain firearms, or, more recently, the personal manufacture of a firearm with a 3D printer and/or CNC machine. GG makes no claim regarding your local manufacturing legalities. In some localities, lower receiver files provided by Ghost Gunner may require special licensing to manufacture and/or possess.

Under federal law, manufacturing firearms for purpose of sale and distribution without an FFL is prohibited. Without an FFL, you should manufacture firearms for personal use only. Recent ATF determinations have signaled that allowing others use of your CNC equipment may itself constitute manufacturing, therefore Ghost Gunner advises GG owners to neither print firearms for other individuals, nor allow other individuals to use their Ghost Gunner to manufacture firearms without the advice of counsel.

Will the Ghost Gunner be able to finish AR-10/.308 receivers?

GG2 currently supports 308 receivers and we are working to support 1911 frames.

When does my order ship?

All machines are made to order. We sell exclusively to our deposit list in groups of 350 machines. We are now shipping units for Q3 2017. To find out more about shipping timelines and order status, please contact our customer support team at

What is Ghost Gunner?

GG is a manufacturing concern managed by Defense Distributed.

Terms of Service?

Please see our latest terms of service here.