Build your own ghost gun
Polymer80 kit gun (Travis Pike for TTAG)
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Welcome to part one of a three-part series, a joint collaboration between The Truth About Guns, Ammoland, and USA Carry. We’ve started a new project that will include three articles going over the process of building your own Polymer80 GLOCK compatible 9mm pistol and getting it running.

The Polymer80 kit for this project was provided by They sent me one of their complete GLOCK compatible pistol kits. This kit includes the Polymer80 80% frame as well as the lower parts kit, the slide and slide kit, and a small travel safe.

What is an 80% Frame?

Polymer 80 GLOCK compatible build project
The beginnings of a spooky “ghost gun” (Travis Pike for TTAG).

If a gun’s frame or receiver is built, but remains unfinished, it’s not considered a gun…legally speaking. These unfinished frames and receivers are known as “80%” frames or lower receivers (in the case of an AR-15). The idea is that the buyer will do the last 20% of the finish work to make it operate, in effect building his own gun.

That’s something that’s been legal in the U.S. since forever, though now a few states prohibit home builds or require a home-built firearm to be registered and serialized. Be sure you know your state’s laws.

There’s a wide variety of 80% frame and receivers available today, including kits available for AR-15s, AKs, Ruger 10/22s, Sten guns, GLOCKs, and many, many more.

Again, since these are unfinished frames in the eyes of the ATF, the are not considered firearms. That means they can be shipped directly to your home. You don’t have to pay a transfer fee or fill out a 4473 background check form.

Federally it’s perfectly legal to build a gun for your own personal use. As mentioned above, however, that freedom varies among the states, with the demonization of home-builds as “ghost guns.”

A few states have regulated 80% builds, so be sure to check your state’s laws. The only other caveat is that our glorious Federal government says I can’t make these and sell them to anyone else. That requires a manufacturer’s license, but that’s another argument for another day.

The Polymer80 GLOCK frames are known by their official nomenclature as the PF940 series. They come in full-sized, compact, and subcompact models, as well as a G43 variant.

I went with the PF940C, the GLOCK 19/23-sized variant of these frames for this project. They also come in a rather wide variety of colors including black, FDE, OD Green, Cobalt, Titanium, and Gray.

Why Build Your Own?

Because to hell with gun control. Honestly, if you order a lower or a kit over the internet with a credit card, shipped to your home address, keeping it off the books isn’t guaranteed if someone starts looking hard enough. But building your own firearm this way makes it a bit more difficult to track you than a 4473 form would.

My reason for building one, though, is that I like guns, and I like having projects to work on. I’ve built one of these before and I find it to be fun and interesting. It gives you a very excellent view of how GLOCK pistols work and just how simple they are.

Best of all, at the end of the project, you have yourself a very good 9mm handgun.

The PF940 frames also feature better ergonomics than factory GLOCKs as far as I’m concerned. Especially the models prior to the Gen5 guns. They lack finger grooves, have a more 1911-ish grip angle, and feature a more aggressive undercut in the trigger guard.

There is also a more pronounced beavertail to the rear of the grip. I’ve a frequent victim of GLOCK slide bite, but not with this particular pistol.

The Polumer80 frams also feature a normal Picatinny accessory rail as opposed to GLOCK’s weird proprietary rail. The subcompact models have rails, including the G43 variant (GLOCK doesn’t offer that).

If you don’t go the kit route, there’s also the attraction of buying your parts one piece at a time and getting the exact components you want. I can certainly see why it’s easier to do get the parts you want up front and have it done rather than swapping out parts.

What You’ll Need to Finish the Kit

polymer80 pistol build tools you'll need
You don’t need any fancy tools to complete the build (Travis Pike for TTAG)

The Polymer80 kits come with a simple clamp-on jig, as well as the two bits and the endmill you’ll need to finish the pistol. In terms of tools, you can finish the frames a variety of ways.

A guy on Reddit did one with no power tools at all. I used a Dremel, a hand drill, a mallet, and a few punches, tools most people will have or can pick up very affordably. I also used a vise, but in my last build, I didn’t need one. A vise does make things much simpler, though, so if you have one, I recommend you use it.

Polumer80 80% pistol build project
Polymer80 jig with pistol frame inside (Travis Pike for TTAG)

The vise makes the process nearly idiot-proof, although, as we’ll see in this series, I’m a bit of an idiot. Once the jig is snapped over the frame, everything you need to do is aligned and ready to mill. There are no adjustments needed, and it’s all Dremel and drill work after that.

What’s in My Kit?

Polymer80 PF940C™ 80% Compact Pistol kit

My complete pistol kit is pretty simple. I used a PF940C frame with a 9mm slide kit produced by 80-Lower. It’s a simple slide with forward and rear serrations and is all black.

I like that, for the most part, the kit is all GLOCK OEM parts. Nothing against the aftermarket, but the Polymer80 PF940C kit was built for GLOCK parts, so that’s the route I wanted to take. It may not be fancy or “custom,” but it will be reliable.

The barrel and trigger assembly that’s included with the kit (Travis Pike for TTAG)

So that’s the lowdown on 80% frames, why you’d want one and what a kit gun like mine includes in the next sections, we’ll go through building the gun and then making it reliable.


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  1. I’ve really been thinking about doing one of these. I love these and the 3D printing types of articles.

    • I’ve built several P80s, in all three frame sizes (G17, G19, G26). Just helped a buddy do his first one a couple of weeks ago. First time, it’s a bit of a hassle. By the time you get to the third one, you can do it in your sleep and come out with a perfect fit.

      From the article:

      “…our glorious Federal government says I can’t make these and sell them to anyone else. That requires a manufacturer’s license,…

      Really? Are we still spreading this false nonsense? By now, after how much this has been discussed, everyone should know it’s only an intent to transfer or sell at the time of assembly that makes it illegal. If you make one without such intent, and later decide to transfer/sell, our “glorious Federal government” has stated that it’s okay because you’re not in the business of manufacturing.

  2. I wouldn’t order online with a credit card if I wanted an untraceable gun. I would try to find a brick and mortar dealer and pay with cash.

    • Good point and even I bet ip address that is used to watch videos or read articles about “build you own gun” are all recorded at the mine.

  3. When is p80 coming out with gen4 compatible frames? Come on guys! I have a g19mos that needs an od green frame and I like the price and look of the p80 stuff.

  4. I like havibg a warranty which is why I buy new guns mostly. With a DIY gun you’re not getting a warranty.

      • That’s the best part about assembling guns yourself. That and the return process is much quicker than sending it to the off-site manufacturer.

        • It’s like making cookies:

          Step 1: follow the instructions
          Step 2: don’t get creative with the recipe.
          Step 3: take your time and do it right.

          Voila! Anybody can do this.

  5. Just checked their website. Price for the whole gun build kit is $590.00. They are out of stock on all of them. This might be the time to buy stock in Polymer90.

    • Glock Store sells the SS80 frame. It’s their version of the G43. I have one. 🙂

  6. If I was to do something stupid like this I wouldn’t build a crappy glock. Hell I wouldn’t even buy a crappy glock. That shit is for fanboys.

  7. I’ve done two… get yourself some “end cutting pliers”… (google it)…. makes things real simple to make the side trims…

  8. I keep procrastinating on mine. It’s the 17 size as I wanted mine more for a range toy. I’ve had it for a couple years. I wanted to make an optics ready gun. There are optics cut slides that come out every so often.

  9. STOP spreading the BS “ghost gun” crap!
    Americans have always been able to make their own firearms.
    So Polymer80 (and all the rest) are just a DIY firearm.

  10. I’m always puzzled by “gun guys” who cast aspersions or scoff at home built/home assembled guns like these. Frankly, EVERYONE should build a few of these, for a myriad of reasons, not the least of which that everyone should have an off-paper gun or two. Or ten.

    But to hear gun guys say stuff like “pfffft, I’d NEVER build a gun, especially a crappy plastic one like that” or “but it doesn’t come with a warranty”….. it makes me question lots of things about you. Like maybe guns just aren’t for you.

    Are they easy to build? Yes and no. Your first one will be tedious, especially rails-to-slide fitment and honing/polishing, and getting it functioning 100%. But you’ll learn things along the way, and that will make you better not just at the next build, but on maintaining, cleaning and troubleshooting other guns, not just P80’s. You’ll start to understand WHY problems happen, because you’ll be much for familiar with how the guns function. And how to fix stuff that would’ve made you shrug and think about selling “that piece of junk”.

    I’ve built over a dozen P80’s in various configurations. My first one took hours to complete, and then days of tweaking, filing, honing, polishing and fitting to get it to the point where it would fire without a hiccup. But the whole time I was learning. Little tips and tricks that save time and headaches. Now, I can do a build in under 30 minutes that is 100% functional, with an action that is as butter-smooth as any pistol I’ve ever owned.

    I look at people who haven’t built/don’t aspire to build a kit gun the same way I look at guys who don’t know how to change a tire or engine oil.

    • I’ve built several as well, in all three major sizes, with another one lined up as my next build. Only two of them needed “fit and finish” tweaking to get them to run smoothly. All the others assembled and performed perfectly right away.

  11. I can see where the author made the “idiot” mistake he mentions. Look at the pin by the grip backstrap in the first picture. Looked like he used the M4 bit instead of the M3 marked on the jig. The hole is clearly too big.

    • It sure does appear that daytime to break out the JB Weld or epoxy as he can fix his mistake.

    • I saw that and thought, “Travis could potentially land a job as a gun craftsman….. at Century Arms!” Definitely an example of WECSOG.

  12. They are addictive and like Lays we’ll make more, They will cure the Ills of Gaston’s frames, he wasn’t willing to listen to what his customers didn’t care for because he created perfection .No more slippery grip textures, no more Glock hump,no more Glock knuckle,many ills to miss but not much to not like with the Poly 80

    Polymer 80 did listen and gave folks what they wanted in the way of a frame and by doing so came much closer to perfection than Gaston ever did.

    At some point every Glock I own will have a frame much closer to perfection,One can ,build a complete gun or build the frames to replace less than perfection.

    If a person isn’t handy with basic tools they can even purchase serialized frames or complete guns, so they too can have a Glock pattern hand gun closer to perfection.
    With the G 44 I last purchased I’ve bought my last Glock as they. don’t build anything better than what I can build with Polymer 80..

    If you would like to try your hand at building a Poly 80 go to you tube and search Marine Gun Builder for all the tutorials need to build yours.

    • I’d add for folks that still have a stock glock frame, modify it using a dremel with a sanding drum bit. The easiest is the trigger guard undercut, then there’s a double undercut. Another improvment is the scalloped mag release button, makes it eaiser to release the mag. Removing too much material (and comprimising structural integrity) is the worst that can happen. So watch a few youtube instructuon videos, tape-protect exposed areas not to be worked on, take it slow, remove a little at a time, test fit and function every so often.

  13. I’d be real interested in the Sig if it wasn’t way more for the kit than to get a factory built. Never know though, what with all the stimulus money floating around.

    • That would be after I finish the .50 cal Plains rifle I started a year ago. Might get in trouble having two projects going at once!

  14. Why Build Your Own?

    “Because to hell with gun control. Honestly, if you order a lower or a kit over the internet with a credit card, shipped to your home address, keeping it off the books isn’t guaranteed if someone starts looking hard enough.”
    To hell with gun control – let kids shoot up schools and gangs get away with murder. Felons and crazy people can make this because of no gun control. Be careful what you support.

  15. I’m hoping to see a similar post here about making your own .45 compact ghost gun(a Glock 30/clone).

  16. I am looking to buy a full kit of a ghost 9 mil.can you please let me know of where I can get one?

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