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

“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 jurisdictionsprovided you haven’t drilled holes in anything just yet.

Why would you want to fill out a Form 1 instead of a factory Form 4 transfer? Timemostly. As we write these wordsan online Form 1 takes an average of three weeks whereas even the fastest Form 4 transfer now sits between three and four months.

Cost savings is another measureas most solvent trap kits are available at a significant discount relative to factory silencers (invariably for a reason).

Normally when you purchase a suppressorit’ll sit at your dealer for months — sometimes more than a year — before the federal government approves your paperwork. But it’s faster if you make your own; in factwe did just that in RECOIL Issue 46.

FILTERING “OIL”

We’ll get the only-worth-it-for-memes alternative out of the way first: the oil filter adapter.

About a decade agowe first laid eyes on oil filter adapters; they were originally made by Tom Cole of Cadiz Gun Works and called “solvent trap adapters.” Cole tells usbelieve it or notthat the original intention was to actually trap solvents. Laterthey released their Econo-Cana registered adapter that’s transferred like a standard silencer. 

But this type of filter being featured in the 2019 release of Call of Duty: Modern Warfare really brought them into the world of mainstream memes. While you can find sketchy adapters on Amazon and WishCadiz Gun Works actually manufactured and legally registered oil filter adapters as silencers and even have an oil filter replacement service for when they wear out. 

We teamed up with an SOT to legally register our own. Engraving actually took more work than we anticipated because our adapter didn’t have enough surface area. A stainless steel washer was welded to the base for this purpose.

Sohow effective is it? Setting aside that it makes most pistols a single-shot affair because there’s no way to attach a boosterthe ungainly size that blocks sights on both rifles and pistols and the massively increased weightsimply put: It’s not all that quiet. An oil filter silencer essentially is a simple expansion chamber that works for a few shots before having to be replaced. And the larger the borethe faster it loses any efficacy.

And oh yeah — you can’t even legally swap out that oil filter unless you’re a manufacturer. 

In a world where silencers are OTC just like a receiverrifleor pistolthese oil filter silencers would make for a fun party tricksimilar to taping a soda bottle to the end of your .22LR. But since legally manufacturing or purchasing adds on $200and you can’t even swap the filter yourself? Hard pass. 

JK ARMAMENT SOLVENT TRAP

This brings us to the exact other end of the DIY spectrumthe JK Armament.

JK Armament is a new companyjust releasing “solvent trap” kits for sale in 2020. Though the company is newthe people behind it aren’t. The namesake of the companyJake Kunskyhas over two decades of experience in industrial manufacturing and weapons design. Kunsky’s company is the culmination of his experience developing products for NEMO ArmsGemtechand Maxim Defense. His background 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.

DESIGN

JK Armament’s first product was the JK 155 Modular Solvent Trap (MST) Kit made for either rifles or pistols. The rifle kit is nearly identical to the pistolexcept the tube is one piece instead of twoit comes with a fixed barrel adapterand the eight stackable baffles are optimized for the higher pressures of rifle roundsso they can’t be drilled so wide.

The name of the game is modularityand it’s certainly evident here. Each baffle section threads right on top of anotherclosely mirroring what we’ve seen from the likes of Schultz & Larsen for the last decadethe Erector from Q LLCthe Dead Air OdessaRebel Silencers SOShalf the product line from Torrent Suppressorsand the new Sig Sauer Mod X.

No need for a tubespacersor mathnor do you have to worry about dubious constructionas you would with a cheap Chinesium kit.

Howeverthese first kits were made from aluminum. Aluminum is just fine for rimfiremost pistol calibersand subsonic 300BLKbut once you start rolling out higher pressuresthe aluminum will quickly erode away.

NowJK Armament does what we anticipated from the very beginningmaking them out of titanium. Aside from being turned from titaniumthe JK 115 SBR Pro kit comes with four baffles instead of eightand a new flash hider endcap is available. If you want a larger kit with more bafflesyou can simply add them prior to manufacturing.

The base tube and all baffles are threaded HUB 1.375×24 TPIso mounts will never be an issue as nearly two dozen companies on the market currently make parts and pieces for the HUB. For pistolsa SilencerCoTorrentor Griffin Armament 1.375 booster will nest insideand JK Armament makes an adapter for those with GemtechSDTAor Liberty boosters.

PLANNING 

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 kitsbut you can buy individual and incomplete baffles at the same time. Want to make a silencer with 10 baffles? You can do that. Want to make your own bastard version of a SilencerCo Wizard Staff? Sure. Want to drill baffles with different aperture sizes in order to make this a modular silencer that’s always caliber-specific? Oh yesyou can do that too. 

There’s some word going around that you can’t register a silencer in a smaller diameter than the bore holesbut that’s hogwash. There’s no regulation or dictate about how large or small each aperture has to be for a given caliberso long as you can put the registered caliber through it in any configuration — just no extras and no spares. Of courseall of this may be subject to change at the whim of the BATFE.

The Enfield Rifle Co Novusas seen here in RECOIL Issue 47 also works on this principle with their nesting baffle stack; it’s a 5.56 silencer that can be assembled to effectively suppress .30-caliber or .45ACP.

There’s currently no reason why you couldn’t make a JK Armament solvent trap kit with 12 baffles with three different caliber aperturesbut we’d recommend Cerakoting or otherwise marking each caliber so you don’t inadvertently get a strike. 

MANUFACTURING 

After we planned out our silencer and received our approved stampsit was time to hit the workshop. The required info was lasered onto the main tubeso we needed to drill the baffles. Kunsky actually advises against using a drill presseven if you have access to one. 

JK Armament solved any centricity issues 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 bit available from JK Armament aligns with a bushing on the jig to ensure it hits center.

The same jig also works for endcapsand since the jig itself is made of aluminumyour vice can squeeze it hard enough that the endcap won’t rotate out when you drill.

With the jig at the readyalong with a cordless drill at a low-speed setting and some machine oilit was fairly easy. If you drill too fast or don’t use cutting oilyou can wreck one of these by chipping it if you’re not careful. Take your timeand you’ll be fine.

After each new sectionwe threaded the completed baffles on top of each other to confirm alignment. Make sure you clean the baffle wellor else an errant chip may mislead you.

AT THE RANGE

The original JK Armament kit was aluminumrelegating it for us solely to pistol calibers and limited use with 300BLK. But with the titanium PRO solvent trap kitwe knew we could press it much further. And press it further we did.

Using a select-fire 10.3-inch riflewe decided not to run one or twobut three SOCOM Table II tests. Table II specifies eight fully loaded 30-round magazines with rates of fire ranging from one round a second to full-auto mag dumps. The entire table is performed with no rest between stagesbut everything should come down to ambient temperature prior to repeating the table.

Effectivelythis is a stress test for the silencer. This accelerated wear gives you a pretty good idea of how the silencer will perform long-term. 

Heat is the bane of titanium. Heat erodes titaniumand you can see it happen in real-time when sparks shoot out of the end of your silencer. There was a time when no one would have seriously considered titanium for anything other than a precision rifle or rimfire silencerbut that was nearly 15 years ago.

All said and donewe fired 720 rounds with this testand while there was noticeable wear on the blast bafflethe others were mostly fine. Butsince this is a modular canyou can simply rotate your blast baffle to the end of the stack to easily increase the longevity of your silencer. And in the worst-case scenario? Have an SOT replace one of the baffles ($125 for a Ti cup$45 for aluminum). 

The flash hider endcap performed exactly as expected toowhich didn’t surprise us because it’s definitely on rather long. For our next buildwe’ll probably trim them down a bit to reduce the overall length. 

LOOSE ROUNDS

You’d be well-advised to add some anti-seize to the threads to aid in disassembly and reconfiguring your can. If you carefully plan your build in advanceyou’ll have a handy silencer that can effectively eat all sorts of ammunition without a compromise like an oversized bore.

When we’re dealing with a new company and a new productthere are typically some warts here and there. Kunsky’s experience definitely shows in this designbringing a lot of advanced features to a home builder that would otherwise require expensive equipment or regaling yourself with eBay parts.

We can’t wait to see what comes from JK Armament next. 

JK Armament “Solvent Traps” can be found here: jkarmament.com

More from JK Armament and about Suppressors

• Watch our RECOIL Exclusive on the Original JK Armament “Solvent Trap.”
• OSSknown for their flow-through Suppressorsjust brought forward both a 9mm and .45 pistol version.
• 3D Printedand Polymer: the MUTE suppressor.
• When is a Integrated Suppressor worth it?
• What is an SBRand why it Matters.

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