$39 Fule fuel Filter Form 1 Silencer Build
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With an e-filed ATF Form 1 (the application to manufacture your own NFA item) taking only three to five weeks (ish) for approval these days, as compared to about nine months for a Form 4 (transfer of an existing NFA item), interest in building your own silencer has increased dramatically.

But what if you don’t have machining capability? Can you convert an existing, non-regulated product into a working suppressor? Let’s find out!

$39 Fule fuel Filter Form 1 Silencer Build

There are a handful of products that are readily converted into a firearm silencer, including solvent traps (see HERE), oil filter adapters (see HERE — and FYI I’m testing this next), and apparently “fule filters.” Whatever that is (and yes, that’s how it’s spelled).

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

Well, it’s this. Presumably “fule filter” is a typo, likely during a Chinese-to-English translation, of “fuel filter.” Obviously the intended purpose of this product is to use it on your vehicle to, like, catch and filter gasoline or something. Sure it is.

But first . . .

DISCLAIMER: I’m not a lawyer, I don’t play a lawyer on TV, and I didn’t stay at a Holiday Inn Express last night. Everything below represents the choices I made while navigating this process. Some err on the extra-cautious side — more cautious than most folks believe necessary — some are absolutely mandatory.

Please be sure to review the relevant laws, consult an NFA attorney, and do your own research related to federal and state restrictions and requirements before proceeding with creating your own NFA item. Calling the NFA laws non-trivial would be a massive understatement, so do not run afoul of them. The penalties for doing so are severe.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

In my quest to be extra cautious, the first thing I did was file my ATF form for approval via the ATF’s eForms system. The Form 1 is not only payment of your tax stamp and registration of your to-be-built NFA item, it’s also your permission — upon approval only — to manufacture said NFA item. I chose to file my form and wait for approval before even buying the product.

In my mind doing it in this order eliminates my risk of possessing something the ATF might consider to be silencer parts before I’m approved to have such parts.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

The second “abundance of caution” choice I made was to purchase from a U.S.-based company. While this “fule filter” could have been made abroad, it did not ship to me from abroad. I chose a company that ships from domestic inventory.

It’s my understanding that some of the folks who ordered these sorts of things off of the Wish.com or otherwise via Chinese retailers and then received visits from the ATF were, at least in part, accused of importing silencer components.

It’s also my understanding that none of them waited on an approved Form 1 before receiving their parts. Again, this isn’t a legal requirement assuming the parts are not legally silencer parts, but I chose to do this just in case an argument could be made, as it apparently has been, that they are either silencer parts or are intended to be silencer parts.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

With Form 1 approval in hand, you are now the legal manufacturer of the silencer that you’re going to create. This means you must engrave all of the appropriate manufacturer markings onto it. Model name, serial number, caliber, your name or the name of your trust or business, and your city and state. This must match the information you provided on your Form 1.

NOTE: Complete the engraving before actually doing the necessary manufacturing to turn your “fule filter” into a firearm suppressor.

As you can see above, I’ve deemed this suppressor the POS9MM and have given it serial number POS9MM-1. As a co-owner of Black Collar Arms, which is an FFL 07 and SOT manufacturer and the actual purchaser of this $39 fuel filter, I registered it under the company name.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

Turning a fuel filter into silencer is, in this case, simple and straightforward. See the end cap above, sitting between the aluminum tube and the aluminum monocore filter structure? Obviously it’s solid in order to capture the automotive fule inside of the filter baffles — much like a solvent trap.

Drill a hole through it and now it’s a silencer end cap. That monocore filter set is now a monocore suppressor baffle stack. Amazing!

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

Slide the tube over the baffle then thread on and tighten the end cap to lock it all down. I suppose the silicone fuel line they sent can go in the trash. Ready to rock!

Here’s the range test video:

I chose to purchase a — ahem — fuel filter that’s threaded 1/2×28. This is the typical thread pattern of .22 LR and 9mm suppressors, which I figured were appropriate calibers for use with an all-aluminum silencer. Centerfire rifle rounds were going to be beyond the capability of this material…though you know I tested it anyway.

With a fixed mount — in this case the threaded mount is integral to the monocore — it’s unlikely that my new suppressor would work on a semi-auto pistol that doesn’t have a fixed barrel (meaning nearly every 9mm pistol out there). Due to the suppressor’s light weight, though, it’s possible that it would work on some handguns even without a booster (“piston” / Nielsen Device). I intended to test this and brought a pistol to do that, but ended up blowing up my POS9MM before I had a chance.

Anyway, first up was testing the can with .22 LR. I threaded the POS9MM onto the end of a Radical Firearms 10/22 and went to town with both subsonic and supersonic ammo, testing the Franklin Armory 10/22 Binary Trigger at the same time.

I was highly impressed! My $39 (yes, you still have to pay your $200 tax stamp, so $239) fule filter suppressor absolutely holds its own against commercially-available .22 LR silencers. No question it wasn’t quite as quiet as the SilencerCo Switchback I had with me, but it was far closer than I could have ever expected and it’s fair to say it was super quiet.

Would I legitimately choose to purchase a $39 “fule filter,” pay my $200 tax, engrave it, and turn it into a cheap-o rimfire silencer? Abso-freakin’-lutely. The fact that I can file a Form 1 and be on the range using my suppressor within a month is huge. Not to mention a couple hundred bucks or more in savings as compared to a commercially-available silencer.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

Switching over to a 9mm pistol caliber carbine with a 16-inch barrel, I was similarly impressed. I found the POS9MM to be on par with the GEMTECH Lunar 9 when the Lunar was in shorty configuration. Needless to say, this once again far exceeded my expectations.

That said, the Lunar 9 in shorty mode is designed to be as compact as physically possible while staying just this side of the “hearing safe” 140 dB threshold on most setups, so it isn’t particularly quiet in short configuration. With the Lunar 9 in its full length configuration, it was noticeably quieter than the POS9MM, but not by as big a margin as I would have guessed prior to testing.

Would I go through this process to create a 9mm PCC suppressor? Yeah, possibly. It doesn’t hold its own against “real” silencers (Form 4 silencers) from “real” companies as closely as it does on .22 LR, but it’s still a perfectly functional, legitimate suppressor and it should hold up perfectly well for many thousands of rounds of 9mm use.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

What it will not hold up to, though, is centerfire rifle use. That’s no surprise. Aluminum — particularly what I assume is not the highest grade aluminum and it clearly isn’t hardcoat anodized — simply isn’t up to the task of dealing with the pressure, heat, and intense particulate blast of rifle rounds.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

So naturally I put the POS9MM on the Brownells BRN-180S setup with its 10.5-inch barrel firing full-power .223 Remington. Bore erosion was dramatic after only 35 or so rounds. That supersonic particulate ate away the aluminum like mad.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

Unfortunately that was the least of the POS9MM’s problems. Between the first and second baffles, the aluminum monocore began to stretch almost immediately. One or two shots in and gas was already leaking, violently between the end cap and the tube as the monocore had grown longer and the seal was broken.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

And that’s not all that broke. At 35-ish rounds most of the monocore flew downrange, having separated at the stretch point between the first and second baffles.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG
$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

The moral of the story here is clear: an aluminum “fule filter” turned suppressor isn’t going to hold up to centerfire rifle rounds. Stick to rimfire and pistol fodder.

$39 Fule fuel Filter Form 1 Silencer Build
Jeremy S. For TTAG

Believe it or not I consider this to be a big success. For $39, a tax stamp, and only three to five weeks wait time one can have a great .22 LR suppressor and/or a decent 9mm suppressor with personalized markings. That’s hundreds of dollars and many months less than purchasing a typical silencer from a commercial silencer manufacturer.

Just don’t forget your fule filter silencer’s limitations.


•  It was intentional that I didn’t link to the website where I purchased this product, as I’m hesitant to encourage or endorse this specific seller, product, or process.
•  There is regulatory risk involved here. None of the above is legal advice, it’s simply what I did to navigate this process as safely and as legally as I knew how given the information I had at the time for the purposes of this post. Proceed at your own risk.
•  Black Collar Arms, as an FFL 07 / SOT, files a Form 2 for this kind of stuff, not a Form 1. That changes nothing about the process other than, as a manufacturer, there is no $200 tax and approval is typically even faster.

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  1. I’ve wondered….now that you’ve destroyed an NFA registered item…do you have to report this destruction to BATFe and how do you document the destruction to their satisfaction? …or, as the “manufacturer” can you replace the core with a new one? Is there an additional Form 1 (in your case Form 2) to fill out with the resultant waiting period / approval for “re-building” the registered item?

    Not asking for a friend…just curious.

    • Not personally.

      A form 1 suppressor must be sent to a FFL SOT07 for repairs. Luckily, he’s an SOT07. He can send it to himself.

      But what’s the point? He could buy another fule core – but limit his use to 22 only.

      I wouldn’t use alum for anything but .22, and even then, you can’t dip it to get the lead out.

      The Form1 route is a novelty – and you’d be best spending a little more money on quality for that $200.

      • “I wouldn’t use alum for anything but .22, and even then, you can’t dip it to get the lead out. ”

        Folks who don’t know should be aware – Caustic (a high-PH chemical, like drain cleaner) being used to clean aluminum will dissolve it. Ruin it. Destroy it. Many ‘carbon-cleaning’ ultrasonic bath solutions sold as silencer-cleaning solutions are high-PH, and will ruin it.

        2 questions for Jeremy (who may or may not have spoken in class as a child) :

        1 : Jeremy, if I elect to go this route (and I most likely will!) could Black Collar Arms engrave my legally-registered can, and if so, how broke would it make me?

        2 : The BATF does not allow the end user to replace suppressor components, like the rubber discs used (to great effect) in some tiny rimfire cans years back.

        If that’s true, why does the BATF allow water or cable-pulling gel to be used to make them quieter? All are physical objects placed inside the suppressor, with the intent to make them quieter…

        • There are probably many laser engraving places in your area, including places that do trophies and photo frames and such. You could bring the tube to one and have them do it. To be fully on this side of the law, you’d have to be present since leaving it with them would put them in possession of it and that’s not cool unless they have an SOT. But any place that engraves would do it and only charge a few bucks.

          As for the repair questions here, yeah, it isn’t legal for a non-SOT to repair or replace suppressor parts. So even though you’re the Form 1 maker of the suppressor, once you build it (including even if you were to machine the entire thing from scratch yourself on a lathe in your garage, for instance) you cannot repair or replace or physically modify it. An SOT, however, could. Potentially an SOT could order another $39 fule filter and replace the baffle for you.

      • Glad you think following the law is a “novelty”.

        You’re going to spend that $200, if doing things above board, regardless if it’s a eForm 1 or a Form 4.

        I have done the then $25 solvent trap to legal suppressor. Total cost (trap, engraving, stamp) was $240 and I was shooting it in less than a month.

        The non “novelty” route (suppressor, stamp) would be in the neighborhood of $400 and a 6-12 month wait.

        As the author noted, there was hardly any audible difference between his Form 1 can vs a “factory” Form 4 can.

        • Brad, I take no offense at his terminology, since the “law” referred to is clearly unconstitutional, and therefore void.

        • Yes, if it can do 9mm out of my Ruger Carbine and pistols I think I will attempt after my current shotgun. project.

          I’m not going to spend what amounts to a new firearm on a store bough suppressor. Prices are steep even for a quality .22

    • for a destruction of a NFA I read most dealers take pictures of the item with the proper tourch cuts or approved crushed methods and send a certified letter to the atf branch with the pictures.

      • Thank you…makes sense.

        What doesn’t make sense is that, apparently, you can legally build (with a Form 1) a suppressor…but, you cannot legally repair said can, when damaged, yourself.

  2. Ok

    I’m sure someone will correct me, but why as an SOT07 would you pay $200 for a Form 1 and register the suppressor as owned by the SOT, when you could have made it “tax stamp free” on a Form 2?

    You wasted $200.

    Second, you are the “maker” aren’t you on a form 1 — not the manufacturer (at least that’s the case for SBR and SBSs). (“ With Form 1 approval in hand, you are now the legal manufacturer of the silencer that you’re going to create.”)

    If you’re an SOT07, be an SOT07…

      • You make your own SBR, suppressor and destructive devices on a form 1 electronically. Not particularly special or complicated about it. Just give the king his silver and be knowledgeable of the laws governing those items. I still get the stink eye from fudds on the gun club range with my toys but F them.

        • Wait, now, you’re getting my attention. To “make” a .300 blk SBR like mine, all you need to do is buy a .300 10.5″ upper, then couple it to a normal AR lower. What’s to stop you filing a Form 1, and when the approval comes back ordering the upper and you’re off to the races? I doubt that would save a lot of money (since you’re buying commercial parts), but seems it would be a heap faster!

        • @Larry…nothing. I made my SBR’s by going this route. The wait time was longer then tho. I also worry that having AR pistols AND rifles….what is to stop an overzealous BATFE agent and prosecutor from saying you possess with the intent of making a SBR….perhaps having a stamp for one (or more) affords some protection?

        • Yeah, Larry, that’s exactly what you do. You already own a lower and you use that as the basis for your Form 1. When you’re approved, you engrave the lower and then you order the upper or you swap the barrel on an existing upper or you build an upper, etc etc, and you pair it with the lower. Same thing for, for instance, a short barreled shotgun. File the Form 1, engrave, then chop the barrels down or swap for a shorty barrel when approved.

          With eForm Form 1s taking a month or often less these days, it’s even more appealing.

        • Are you suggesting a suppressor, SBR receiver, and grenade launcher could all be built together with the same serial number on one $200 form 1? Could they then be separated?

      • I think he already did. That’s where the $200 tax stamp fee comes in. Unless there’s something more that I’m missing…

      • “Maybe so he could tell us peons how we can do the same thing without being a SOT07.”

        In your particular instance, I don’t believe you can in California, as a Joe-Blow peon.

        Aren’t NFA ‘toys’ verboten to regular folks in California?

        • The ‘prop companies’ aren’t in any way, shape, or form a regular California citizen…

        • I’m no legal expert. But as a CA resident I’m not aware of anybody outside of official circles being allowed any NFA goodie. Hell, we can’t even have a single shot chambered in .50bmg. No Taurus Judge revolvers. No shockwaves.

          I better stop now before I burst into tears.

  3. Legal question……..since the original suppressor has been destroyed, can you use your existing Form-1 to build another with the same manufacturers info engraved on the new suppressor???

    • No. You can repair it by sending to a FFL 07.

      It’s a no no to ever reuse the same S/N on a different can. The atf has secret cameras in your garage and can see that you did that. I’ve heard sometimes if you put in your safe all broken that if you wish real hard sometimes it will fix it self auto magically. But that’s just a rumor.

      • You have to leave cash in the safe next to it. If it does not work after a week, add more cash. Still no self repair? Add gold.

        • Ever read “The Mote in God’s Eye?” If you left food out at night for the “Brownies” that you’d taken aboard your starship, who were multiplying like rats in the walls, they’d repair whatever device you left with the food, modify your pistol to fit your hand better….

          Of course they eventually overpopulated to the point they destroyed your ship….

      • Put it your safe or cabinet and use the Mending Key, which allows a cabinet to restore damaged objects to their original form.
        (Locke & Key, S1E8 “Ray of F**king Sunshine”)

      • This is sounding nuts. It was my impression from years back that if you owned an M16 which was properly registered etc, that when it got old and weak you could send it in to the manufacturer, pay a standard price, and receive a brand new gun with the same serial number. You’re saying no, you can throw your $20,000 toy in the crapper?

    • Quietbore

      White Trash Tactical

      JR Enterprises



      Google any of those with “solvent trap” next to it, and you will find load of information.

      There are entire online communities around this.

      You want stainless steel or titanium for center fire rounds. the thicker the cups/baffles, the better. Arrangement is more of an art than a science, and there are many techniques to baffling the sound. It is not as simple as a hole through a baffle.

      I built a Quiet Bore .30 Cal Form 1 Can and I use it to suppress my competition rifle. It does great. I periodically check the baffles for strikes or damage and its doing really well after a hundred rounds. It is heavy though, so I recommend going with another brand if weight is your priority.

      You can do a full titanium build for about 400-500 plus the stamp so youre starting to get into commercial Form 4 products (but at a 21 day wait time instead of 9 months).

      I honestly think the Form 1 route is the way to go for suppressors until the ATF implements E File for Form 4, or suppressors come off the NFA

    • I used to get bombarded by Google ads for a Chinese company that had titanium and stainless steel options for their fuel filters, but BATFE later seized their website. So, theoretically, there’s something that can stand up to center fire rifle, but I don’t know if it is structurally sound, properly heat treated, etc.

  4. Thanks for this Jeremy.
    I hope it will save folks money.
    I was actually considering something like this due to the wait times.
    I’ll pass.
    In true “me” form. I want ONE. One silencer.
    One that will quench the .375H&H, and my .22’s.
    9 mil to .45.

    Just let me change the end caps and be a responsible person.

    OK. Maybe not the .375. Or the .416. Or the .470. Or the .600 I’m looking at.

    • You can do it with 2 for sure a .22 can and a hybrid covers everything I suppress my 300 blackout bolt and ar pistol, 1911, and even a 44 magnum single shot. It sounds good on everything waiting on a resonator r2 now for those couple decibels. I’m thinking about doing a form 1 integral pin and weld on the bolt action blackout…

    • Mater is right, Tom. If you want to do silencer, but don’t want to get into a full-blown stamp collection, you still really need two.

      Something like the Silencerco Hybrid, or Griffin Bushwacker will suit most of your centerfire applications, there is no substitute for a proper .22 RF can- they are sublime, and relatively cheap. Once you have tried a 3-4oz can on your .22s, the pound and a half do-all centerfire cans will feel absolutely ridiculous on your rimfires.

      From the sound of what Jeremy found out with his fule filter, that might not be a bad place to start for the rimfire can.

    • Tom, if you look at a can for a .50 BMG, and imagine carting that thing around to shoot your .22, you’d see 2 are advisable.

  5. Fun test! Thanks for posting. I would have liked to see how it worked and survived with subsonce .300 BLK out of an AR pistol. Maybe next time….

    • Me too. I planned on it but then I got ahead of myself and skipped straight to blowing it up before testing on other guns haha …but also, in this case it’s a 1/2×28 thread pitch and that makes 300 BLK very difficult. I did mean to try it on some other stuff, though, but jumped straight to the punchline lol

      • Ladies and gentlemen: the always necessary and never redundant words of the inestimable ‘I Haz A Question’. As it was, is and ever shall be.

        All Hail.

        • You are one to speak about redundant and unnecessary words! I have yet to see anything you say that pertained to the discussion. Why don’t you do yourself a solid and stop being little obnoxious fool?

      • “But you don’t have to register a fluffy pillow, right?”

        Ask your lawyer the definition of “Constructive Possession”, and how it can affect you in a very negative way… 🙁

  6. Can’t have a silencer in ILLinoyed. Life’s ruff and I’ll lose more hearing. Whut? Aaaaas? Huh? Interestingly(?) Warrior Poet Society guy claims he would let er rip in home defense-hearing be damned…scare the baddies. Cavalier from being ex-miliary I guess.

  7. Curious – Why hasn’t whoever is selling those ‘kits’ from a USA location been raided by the BATF yet?

    • I mean, it’s perfectly legal to sell fule filters and solvent traps and all this sort of stuff. They’d have to prove that they’re intentionally designed and sold to become firearm silencers in order to make a case that they’re silencer parts and the company is illegally selling them outside of the NFA regulations. This website makes ZERO mention of anything of the sort. I’m just a guy who bought a fule filter and decided to use it in a personal project to see if I could re-manufacture it into a passable silencer. Perhaps companies that got raided for selling “solvent traps” and whatnot actually advertised that they were making them as Form 1 suppressors? Really not sure. But this thing is strictly advertised as a fuel filter and I chose to misuse it and perform necessary machining in order to even make it functional for attempted silencer use. So the ATF may not have a leg to stand on. Doesn’t mean the doggo is safe.

  8. I think this is the most info I have gotten from TTAG in a long time. I am VERY new to suppressors. I personally only have one, a Gemtech GMT-300, and have barely put any rounds through it. Probably because finding .300 subsonic is like finding a great white buffalo right now. I am actually ashamed how much I paid for my Hornady black, but I got it so ha ha na na na boo boo!

  9. Biggest thing I’ve learned from this article and comments is that the ATF needs scaled back and the NFA needs to be eliminated. Once rules and regulations get to the point that the establishment cannot keep a clear and precise degree of organization or intent it becomes time to reevaluate its necessity.
    Fear driven laws of 100 years ago need to be looked at.
    A law stating that its unlawful to have more than 6 spokes on a wagon wheel is about as useful as one saying short barreled rifles are dangerous when pistols, arm braces, and AOW’s exist.

    If its not about control, then they would fix these laws right, so then it is about control, and if it is, then shouldn’t we eliminate that issue?

  10. Beware, I found the “Fule Filter” and the website states that these are now shipping from China as their domestic warehouses are out of stock. Shipping from China may involve a visit from your favorite convenience store.

  11. So is the consensus that this (or any aluminum) will stand up to 9mm?

    I don’t have much interest in a rimfire only can.

    • There are tons of commercially-available, aluminum pistol cans. They do great. The only reason I shy away from them is that it’s easier to clean stainless steel or titanium since it’s tougher so you can scrub harder, you can put in an ultrasonic tank, you can use “the dip,” etc. But, otherwise, 7075 aluminum, especially if hardcoat anodized or DLC treated or something else, is fully sufficient for handgun rounds under normal conditions.

  12. How is completing an 80% suppressor any different than completing an 80% receiver, say like on a Ruger 10/22, for personal use only, which does not require an ATF license?

    • It’s not….except “they say so”.
      Title 1 firearms are (currently) not infringed. Anything under NFA is super scary and infringed.

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