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RECOIL Exclusive: JK Armament “Solvent Trap” Kit

[Editor's Note: JK Armament does not produce so-called ‘solvent traps' as they are no longer allowed by the ATF. You can read more about solvent traps in RECOIL #52 and also in the book DIY Guns. This article is for educational, historic, and entertainment purposes. However, JK Armament is alive and well–and you can learn about their latest in RECOIL #64, or online here]

Normally when you purchase a suppressor it'll sit at your dealer for months, and sometimes more than a year before the federal government approves your paperwork. But it's faster if you make your own; in fact, we did just that in RECOIL issue #46.

[For an in-depth look at submitting a BATFE Form 1 online check out our article here–and pay particular attention to the part about required markings.]

“Solvent Trap” is the current underground moniker for parts and kits used to manufacture your own silencer with an approved Form 1. These are perfectly legal in most jurisdictions, provided you aren't drilling holes in anything just yet. After your markings are made and your Form 1 is approved, it's building time. But a little bit of advanced planning can make for a helluva versatile can, especially if you use what we're about to show you.

As to why one would want to fill out a Form 1 instead of a factory Form 4 transfer? Time, mostly. As we write these words, online Form 1's take an average of three weeks whereas even the fastest Form 4 transfer now sits between three and four months. Cost savings is another measure, as most “solvent trap kits” are available at a significant discount relative to factory silencers (invariably for a reason).

JK Armament is probably a name you've never heard, but the man behind it certainly has experience. It's the pet project of Jake Kunsky, who has over 20 years of experience in industrial and weapons machining, ranging from making automotive and farming parts to silencers and firearms. Kunsky tells us he gained exceptional hands-on experience over the course of his four combat deployments to Iraq, realizing his passion for weapons development along the way.

What you see here in JK Armament's product line is the culmination of Kunsky's experience developing products for NEMO Arms, Gemtech, and Maxim Defense. His experience with silencer design and engineering gives him unique insight into what today's customers are looking for in a user-configurable and maintainable solvent trap.


Which brings us to JK Armament's first product: the JK 155 Modular Solvent Trap (MST) Kit.

We took a few minutes to give you a brief overview of the JK 155 MST with a short video:

The name of the game is modularity, and it's certainly evident here. Each baffle section threads right on top of another, closely mirroring what we've seen from the likes of Schultz & Larsen for the last decade, the Erector from Q LLC, the Dead Air Odessa, Rebel Silencers SOS, half the product line from Torrent Suppressors, and the new Sig Sauer Mod X.

No need for a tube, spacers, or math, nor do you have to worry about dubious construction, as you would with a cheap Chinesium kit.

Two complete kits will be available, the JK 155R and JK 155P. One is for rifle, the other for pistol. What you see here is the pistol kit.

While final configurations may change a little bit since we're using a preproduction model, our JK 155P MST came with eight stackable and undrilled cones, an undrilled endcap, a bridge from the main tube to the baffles, and a booster adapter. These baffles can be bored out to accommodate up to .45ACP.

The rifle kit is nearly identical, except the tube is one piece instead of two, it comes with a fixed barrel adapter, and the baffles are optimized for the higher pressures of rifle rounds, so they can't be drilled so wide.

The base tube and all baffles are threaded in the new universal silencer standard of 1.375×24 TPI so mounts will never be an issue. Everything with this model is anodized 7075 aluminum, but we anticipate further material choices and designs will be available in the future from JKA.

The JK 155 MST kit also came with a set of 3D-printed tools, and the STL files for them will be available on the JK Armament site if you want to print out your own set.

One of the major issues with this type of kit is properly locating the center hole for drilling. There are many pre-mades on the market that use a simple dimple for indexing but they are astonishingly easy to get wrong (there's a reason why places like SilencerCo use wire-EDM to ensure concentricity). Ensuring your holes are centered is always important, but it's absolutely paramount with a tubeless design where baffles are stacked.

And looking at a JKA cone, you begin to wonder where in the hell you drill in the first place, seeing as how instead of a dimple there's a nipple on these undrilled baffles.

JKA solved the centricity problem with a custom drilling jig. It's meant to be used with a hand drill and a vice – no need for a mill here, the undrilled baffles simply thread onto the jig. A caliber-specific drillbit available from JKA is aligned with a bushing on the jig to ensure its hitting center.

The same jig also works for endcaps, and since the jig itself is made of aluminum the vice can squeeze it hard enough that the endcap won't rotate out when you drill.


We almost want to say assembly here, but the technical term is manufacturing. While these are intended to be used for Form 1 builds, we teamed up with a NFA manufacturer so that not only did we not have to wait, but we could make some modifications along the way if we ran into problems. It sounds ridiculous because it is, but even if you as an individual can legally make a silencer, it takes an SOT manufacturer to fix it or legally modify it. We decided on a 9mm because aluminum just screams pistol rounds or subsonic 300blk to us. 22lr would be another option but with a can so large we determined it would be a waste.

After all required info was lasered onto the main tube, it was time to drill the baffles. Kunsky actually advised against using a drill press, even if you have access to one. With the jig at the ready, along with a cordless drill at a low-speed setting, and some machine oil, it was fairly easy. If you drill too fast or don't use cutting oil you can wreck one of these by chipping it if you're not careful. Take your time and you'll be fine.

After each new section, we threaded the now-complete baffles on top of each other to confirm alignment. Make sure you clean the baffle well or else an errant chip may mislead you.

But there's a little more, and here's where planning ahead will help you maximize the utility and versatility of your silencer by making it multi-caliber AF. Not only can you buy the kits, but you can buy individual and incomplete baffles at the same time. Want to make a silencer with 10 baffles? You can do that. Make your own bastard version of a SilencerCo Wizard Staff? Sure. Have baffles drilled with different aperture sizes in order to make this a modular silencer that's always caliber-specific? Oh yes, you can do that too. Your suppressor will be just fine (and you're getting approval first anyway) with several different hole sizes provided, everything can be assembled and used together (no spares/extras allowed) and it'll shoot the listed caliber regardless of configuration. Of course, all of this can be subject to change at the whim of the BATFE.

The Enfield Rifle Co Novus, as seen here in RECOIL #47 also works on this principle with their nesting baffle stack.

Here's a simple example of something you could make:

JKA is also producing an adapter so this kit, along with any other 1.375×24 TPI suppressor, can accept booster assemblies from Gemtech, Liberty Suppressors, and SDTA. While Gemtech steered away from their legacy piston of yesteryear with the Lunar-45, they recently brought it back with the launch of the Lunar-9. All of these booster assemblies are readily available, which is why they're popular with homebuilders.

Ideally you'll want a booster assembly that fits more flush to the can itself, and those can be purchased from Griffin Armament, SilencerCo, Torrent Suppressors (pictured above), and more.


We tested our 9mm build first with pistols, and then a select-fire CZ Scorpion. While the sound and tone were good (we found five baffles to be about right for subsonic 9mm) the pressure was very high inside the silencer. There was a lot more lead and metal debris than you would normally find.

We highly recommend you clip your baffles to alleviate this a bit, which is what we did immediately following the first range session. Do some research on which method you want to use for clipping; remember that this isn't a welded stack and it will be virtually impossible to line up asymmetrical cuts. Your best bet here is to use a file to put symmetrical clips on your baffles like we did here.

Federal Syntech 150gr quickly became the round of choice for this one. We even tried it with a single baffle installed, but we cannot recommend it. Still, an SBRd Glock is always fun.


You'd be well-advised to add some anti-seize to the threads to aid in disassembly/reconfiguring. Because this model is aluminum we'll shy away from high volumes of high-pressure rounds like 5.56mm at the moment, but what we came up with is excellent for 9mm. If you plan your build in advance, you'll have a handy silencer that can effectively eat from all sorts of ammunition without a compromise like an oversized bore.

Normally when we're dealing with a new company and a new product there are some warts here and there. The experience of Jake Kunsky shows in this design, and it brings a lot of advanced features to a home builder that would otherwise require expensive equipment or regale yourself with eBay parts.

The accessories such as the booster adapter (with more to come) are icing on the cake. We can't wait to see what Jake comes up with next.

Full-boat MSRP starts at $499.

[You can visit JK Armament online here]
[Silencer Shop also has them available, rifle here and pistol here]

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6 responses to “RECOIL Exclusive: JK Armament “Solvent Trap” Kit”

  1. Robert Booher says:

    What size did you go on the clipping cuts?

  2. Tom Fleener says:

    Would like to know if my order is going to back ordered for two weeks or is it in stock ????

    • Tom Fleener says:

      I’m not to sure if i would bay anything from these people. they have my money and no way to get a hold of them , no email no phone number . i just want my money (BACK )

  3. JK Armament says:

    We don’t put our number out because we don’t want to spend all day talking to morons like you

    • John Jakes says:

      Would clipping compromise sound suppression in this instance?

      Seems like that would be counter-intuitive if there is good pressure, that’s what we want right?

  4. G says:

    More on the clipping as stated in another comment is it really necessary and if you do decide to do so how would you get the clipping segment to align with one another from baffle to baffle.? What’s JK’s opinion on the matter?

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    • I'm not to sure if i would bay anything from these people. they have my money and no way to get a hold of them , no email no phone number . i just want my money (BACK )

    • Would clipping compromise sound suppression in this instance?

      Seems like that would be counter-intuitive if there is good pressure, that's what we want right?

  • More on the clipping as stated in another comment is it really necessary and if you do decide to do so how would you get the clipping segment to align with one another from baffle to baffle.? What's JK's opinion on the matter?

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