DIY Freedom

The GST-9 from 80% Arms is everything the factory GLOCK 19 might be plus a little more.

The GST-9 pistol from 80% Arms is a DIY kit that allows you to build a GLOCK-style 9mm handgun legally on your dinner table. The end result is as svelte as Cary Grant’s aftershave, as customizable as Angus MacGyver’s Leatherman tool, and as rugged as John Wayne’s jockstrap. 80% Arms sells everything you need to go from a box full of parts to ringing steel on the range in less than half an hour.

Unlike many GLOCK knockoff pistols, the GST-9 really is a top-flight race gun. The cool upgrades you’d typically pay extra for come standard, and the chassis offers certain high-performance options not available in a factory pistol. You also get the personal satisfaction and security of having built it yourself.

Finishing out one of these guns requires a hand drill at a minimum. A Dremel grinder and drill press make things quicker and easier, but you can also complete the project with nothing more than hand tools and a little sweat. If you can change the oil in your car, you are overqualified for this project. The end result is the purest form of liberty ever contrived by man.

Will built this home defense configuration in his garage with a few hand tools,
spiffing it up with a Trijicon RMR and Streamlight.

Snip four of these little tabs back with wire cutters and then smooth.

Details

The 80% Arms GST-9 is a top-end GLOCK-style defensive gun you can legally build at home. There are a few freedom-averse states in our Great Republic that restrict such toys. If where you live sucks that bad you should obviously just move.

According to federal law, if you build a firearm at home for your personal use with no plans to sell it there is no need to serialize the frame or notify anybody. Don’t freak out about that. In our nation of 328 million people there are already some 400 million guns. In the first half of 2020 the number climbed by another 19 million firearms. It’s not like the criminals will ever have any difficulty arming themselves. The GST-9 helps level the field for the rest of us.

The GST-9 is like a GLOCK 19, only better. The custom slide sports lightening cuts, scalloped gripping grooves, and a rear deck with an RMR cut for a red dot. The frame, however, is whatever you want it to be.

The stippling and contours are perfect. Any less and it would be slippery. Any more and it would abrade. The coolest bit, however, is the removable magwell funnel.

These components are retained via a pair of pushpins. The short version accepts 15-round GLOCK 19 magazines. The longer sort takes 17-round GLOCK 17 boxes. Two minutes with a punch lets you choose between a G19 or G19X equivalent as the spirit leads.

The magazine release and slide stop are perfectly scaled and left-side-only. Holsters and accessories designed for the GLOCK interface seamlessly with the GST-9. The trigger is the standard combat-grade 5-lb. striker-fired sort. Frames come in black, OD green and FDE, while the slides are available in black or FDE.

Will once used this medical hand drill to cut a hole in someone’s skull.
It’s since been retired to home gunsmithing duties.

You’ll need to order the jig kit separately per ATF regulations. But all can be
shipped straight to your door — no paperwork of FFLs required!

Whistle While You Work

Some gun build projects require enough support equipment to manufacture an operational spacecraft along with an advanced engineering degree. Not so the GST-9. The $750 kit includes everything but the jig, tool kit and slide rails. The $30 jig kit includes the other stuff, but the BATF won’t let them sell it in the same box with the pistol parts.

I actually built two of these guns for this project. The first I used basic power tools — a modest drill press and a Dremel tool. The second I finished out without using electricity. This meant a hacksaw blade, a pair of wire cutters, a small round rasp, a coarse file, a spot of sandpaper and a most remarkable hand drill.

I once used this very tool to bore a hole through a man’s skull. He had recently suffered a fairly impressive motor vehicle crash and was in no shape to complain. The hole in his skull emergently relieved the pressure on his brain and saved his life.

This disposable burr hole craniotomy set included the niftiest little hand drill. I couldn’t bring myself to discard such an awesome tool, so I scrubbed it down, ran it through the autoclave, and have used it for more than 20 years for minor chores. With nothing more than that simple drill and a few hand tools, you can craft what is arguably the world’s coolest polymer-framed handgun.

Interchangeable magwell funnels let you choose between
the GLOCK 19 and GLOCK 17 frame geometry.

Mechanical Details

The build fractionates down into two phases. Bolt the jig in place around the frame and then use your drill to bore the three pin holes. Each hole must be drilled separately from each side, so that’s six different operations. It takes less time to do than to describe. A drill press helps keep things square and precise, but the manual drill and a steady hand produced a comparable end result.

To finish out the frame, you also need to remove four plastic tabs from the sides along with a bit of leftover material inside the front of the dust cover. A sanding wheel, some wire cutters, or a good sharp knife and a little patience will do the tabs. Snip them back carefully with wire cutters then polish what’s left down flat. Remember it is way easier to take stuff off than to put stuff back on. Shooting the gun some smooths everything out nicely.

Get the big chunks of the semicircular bit up front clear with a hacksaw blade or a cutoff wheel on a Dremel tool. Then dress the area with a round rasp or the Dremel grinder. The build kit from 80% Arms includes both the requisite drill bits, and the proper grinder attachment you need for your Dremel tool.

The instructions are beautifully executed and simple to follow. They claim you can finish the frame in 15 minutes. Move with a purpose using power tools and you’ll be done in less than that.

Once you’ve completed the frame, it’s time to put everything together. There are indeed some tricky bits, but YouTube is awash in instructional videos. If you’re too dim to pull this off, I sure wouldn’t admit that to anybody. It really is a delightfully enjoyable process.

You’ll have to ask yourself if you’re awesome enough to run a gun this
cool that you built yourself at home. Not everybody makes the cut.

Trigger Time

The GST-9 is everything the GLOCK 19 might be, but better. It carries just as beautifully, while the optimized particulars make it a superb combat tool. Magazines leap clear like a six-year-old peeing on an electric fence.
Reliability once everything is broken in is on par with the GLOCK, and follow-up shots are both fast and smooth. I mounted one gun with a Trijicon RMR micro red dot and Streamlight TLR8G illuminator/laser sight and felt ready for just about anything. The GST-9 will reliably take care of business.

This pistol fits my hand like it was born there and is sufficiently reliable to guard my family when out where the Wild Things Roam. It runs just as fast and just as well as a factory pistol while honestly looking even cooler. The fact I made it myself means I know every pin and spring intimately. The kit even delivers straight to your door without pestering an FFL. The GST-9 is a pocketful of DIY freedom.

For more info: 80PercentArms.com, Trijicon.com, Streamlight.com

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