Allen Engineering And The Silencer For The MK12

Credit: LanceCriminal86 -

One quiet day back In 1993, Ron Allen, who was making semiconductor parts for soon-to-be Silicon Valley powerhouses, received a strange telephone call: a man on the line wanted Allen Engineering to build and design rifle silencers. “At the time, I thought it was some sort of sting operation,” said Allen. On the phone was Phil Seberger who ran a garage and basement suppressor business in Shingleton, California. Seberger needed someone with a true machinist’s skill to make parts like muzzle brakes for his company: Ops Inc.

“Phil was a genius and an amazing electrical engineer,” said Allen. “But some of his self-taught machining techniques would make me cringe.” In the late 1970’s and early 1980’s, in the process of designing suppressors, Seberger devised a new technique to precisely measure and record sound waves of a suppressed rifle. Using sensitive microphones and an oscilloscope, he visualized the higher wave length sounds of different baffle designs in his Ops Inc prototypes.

Allen Engineering

Ops Inc/Allen Engineering. Credit DangerDan –

However, the simple task of capturing a screen shot of the oscilloscope output that we would take for granted in today’s high-tech world did not exist in the early days of Seberger’s research and design phases. So he used his electrical engineering skills along with his experience as a photographer in the military to develop a process to take polaroid photographs of the oscilloscope screen at the exact moment the rifle was fired. “It was that technique that allowed him to really refine Ops Inc baffle designs,” said Allen.

Seberger’s innovative testing processes quickly caught the attention of U.S. Army engineers in Aberdeen, Maryland. “They were amazed that he was able to accurately replicate test results in his basement shop against those at the Aberdeen laboratories,” said Allen. With that, Ops Inc’s military and government sales were off and running.

Allen Engineering

Ops Inc/Allen Engineering. Credit GreenGoose –

But, like most geniuses and revolutionaries, Seberger was an eccentric personality. “He could be a difficult person to do business with,” said Allen. In the early days of the Ops Inc and Allen Engineering partnership, Seberger would regularly find other companies who would manufacture parts slightly cheaper than Allen. But after a few months, these companies would usually tire of dealing with Seberger’s behavior and drop the Ops Inc projects all together, leaving him to return to Allen Engineering time and time again.

Allen Engineering

Ops Inc/Allen Engineering. Credit: plante72 –

In the beginning, Allen was helping manufacture the Ops Inc 3rd model for small military contracts in very limited quantities. “Ops Inc couldn’t have produced more than a few hundred silencers before Phil brought me on to help,” said Allen. He believes that the Ops Inc serial numbers must have started at the 1000 mark and can only remember the lowest serial number he’s ever personally seen being around 1050. “Phil’s basement shop was not setup for any sort of volume,” said Allen.

But everything changed with the development of the Mark 12 Special Purpose Rifle (MK12 SPR) by the U.S. Military in the early 2000’s. The custom-designed upper receiver groups were built around the Ops Inc 12th model – an over-the-barrel (OTB) design that requires a specific barrel profile, barrel collar and brake mount. The platform was intended to be nearly silent when measured 50-100 yards away from the shooter, reducing the report by more than 40 decibels (clarification: this was the original reduction value used by Seberger in the beginning).

Allen Engineering

Ops Inc Patent


Ops Inc Patent


Allen Engineering

Ops Inc/Allen Engineering. Credit: m1garand30064 on an Accurate Ordnance platform

The first approximately 100 Ops Inc 12th Models were built by RD Systems in South Beloit, Illinois. But, as it happened so many times in the past, Seberger’s unique personality and budget-minded ways strained Ops Inc’s business plans. As orders rolled in, RD Systems refused to release the first batch of 12th Models to Ops Inc on the grounds of ‘failure to pay’. Eventually, that initial run was released, but the business relationship with RD Systems was over.

That first batch of Ops Inc 12th Models, to Allen’s knowledge, were the only ones not directly produced by Allen Engineering. From that point forward, Allen worked side-by-side with Seberger to help manufacture one of the most successful rifle/suppressor combinations in military history. Whether or not you own a silencer marked as Ops Inc or Allen Engineering, chances are that it was made by Allen himself.

Allen Engineering

Ops Inc/Allen Engineering. Barrel profile specifications.

Allen Engineering

Allen Engineering. Brake mount and barrel collar.


Allen Engineering

Ops Inc/Allen Engineering. Credit: RTUtah – (Length comparison with a mounted AAC suppressor)

But the civilian market was a different story all together. “Phil didn’t want anything to do with civilian sales,” said Allen. “Even with parts as simple as muzzle brakes.” It was around this time when Allen and Steve Thompson from ADCO Firearms realized that silencer sales to the civilian market was the future of the industry. Thompson, who was close friends with the subcontractors of the original MK12 upper for the Naval Surface Warfare Center (NSWC) in Crane, Indiana, slowly convinced Seberger to allow ADCO to sell Ops Inc products on a limited basis. Even so, at one point Seberger actually threatened to kill Thompson for selling brakes that he had bought from a third party. In spite of the threats and personality fluctuations, somehow the trio were able to move civilian sales forward.

Allen Engineering

Ops Inc/Allen Engineering. Credit: plante72 –

As MK12 use increased on the battlefields of Iraq and Afghanistan, the military’s demand for 12th models increased proportionally. Allen stepped up production while also refining his manufacturing processes along the way.

Allen Engineering

Allen Engineering. Models

For a variety of reasons, Seberger had always intended for Allen to take over the Ops Inc business at some point in the future. But after a major stroke in 2010, everything changed – including Seberger’s will. When he passed away later that year, Seberger’s daughter inherited Ops Inc in it’s entirety. The rest of the details between Allen and the new Ops Inc ownership are private. But, it’s safe to say that Allen Engineering didn’t take over Ops Inc or receive any financial gain from Seberger’s estate. In fact, without getting in too deep, Allen suffered significant financial losses as a result of his dealings with the new Ops Inc management.

In 2013, Ops Inc’s FFL/SOT was revoked for alleged record keeping and export fee violations surrounding a deal for an order of suppressors to the Canadian Military. Thankfully, Allen Engineering kept their FFL and their independent suppressor business and continued to produce all of the current Ops Inc designs as “AE” models. “Besides a few less baffle holes, the designs are exactly the same as the Ops Inc models,” said Allen.

Allen Engineering

Ops Inc/Allen Engineering. Credit: BurtSaun1049 –

Allen couldn’t be more modest or easy going if he tried. Where he would be well within his rights to show hate or spite towards certain individuals who have treated both him and his business poorly, Allen just refers to them as “difficult personalities”. All the while he continues to manufacture silencers and, by all accounts, provide some of the best customer service in the industry. Allen could sell barrel/mount/suppressor combinations as a package directly from Allen Engineering, but he respects his relationships with ADCO and other retailers too much to even think about encroaching on their business.

Allen Engineering

Can you identify the Ops Inc silencers?

After nearly 30 years of development, the Ops Inc designs that now live on as Allen Engineering models are still relevant, even in a market flooded with advanced materials and quick detach mounting options. And if you’ve ever had the pleasure of shooting a MK12 you can see why – it’s arguably the quietest 5.56mm semiautomatic setup in existence.


Besides the AEM5 (Ops Inc 12th Model equivalent), Allen Engineering offers other lengths, calibers and mounting options that are solid performers on a variety of different platforms. Retailers like ADCO, Hansohn Brothers, DSG Arms, Capitol Armory as well as others sell current AE silencer models.

I don’t make a lot of suppressors, but every one gets inspected, and finish machined by me personally. That’s why I warranty them for life.

As for the future, Allen is designing a 300BLK suppressor but isn’t ready to commit to a timeline. “The baffle design has to be optimized for the larger subsonic rounds,” said Allen.

So, why isn’t this story entitled Ops Inc instead of Allen Engineering? For one, as a suppressor company, Ops Inc is now basically defunct. Second, Allen has produced the lions share of the MK12 suppressors, whether or not they were marked Ops Inc as the manufacturer.

And finally, Ron Allen is the real hero (my words, not his): Whereas Seberger’s designs and testing techniques were ground breaking, without Allen as well as Thompson from ADCO, the civilian market would have never had the chance to experience highly regarded OTB silencers like the AEM5.

Thank you Ron.

Form 5, brakes/mounts/collars sales to:
Allen Engineering –
11250 Peoria Rd, Browns Valley, CA. 95918-9654

Form 3 sales to:
Allen Engineering –
1201 Industrial Way
Sparks NV 89431

* Allen Enginering does not offer any business hours open to the public.

ADCO Firearms, LLC –
6481 Monroe St.
Sylvania, OH 43560
Fax 419.882.6627
Phone 419.882.8079

Thanks to BurtSaun1049 and the rest of my friends at for keeping this Ops Inc/Allen Engineering discussion thread going. If you are looking for additional details and pictures, stop by and have a good, long read.


LE – Science – OSINT.
On a mission to make all of my guns as quiet as possible.
Twitter: @gunboxready
Instagram: @tfb_pete


  • THE_manBEar

    Wow that’s some stellar gun porn guys … I’m not even sure what this article is about

  • Alex

    Awesome article – I appreciate you taking the time to put this together.

  • Mike N.

    I really like my AEM5. In addition to using it on my Mk12 clone, it works really well on my SBR too.

  • MichaelBolton

    Awesome article, Pete! You unearthed much more than I could have imagined.

    • Pete – TFB Writer

      Thanks for your help! 😉

  • iksnilol

    The Americans can make reflex suppressors?

    HALLELUJAH! I knew you guys could do it… Why aren’t they more popular though?

    • Steve Truffer

      Price, being somewhat limited as to barrel profile and “population” (gasblocks, etc.), and as they were becoming more common, so too were long handguards. Thanks to NFA stamp and lead time, a $700 suppressor + handguard of your choice is much more palatable than a $1000 suppressor + specific brake/collar and other limitations.

      • iksnilol

        Yeah, but imagine an SBR with a reflex on it. You could get it super-short.

        I kinda find it disheartening to chop down your barrel then add a suppressor that makes it longer than it was originally. IE 10.5″ barrel + 8.5″ suppressor.

        • Steve Truffer

          Yes, but again, Its a substantial investment few are willing to make, especially one which comes with extra caveats (must have this much exposed barrel in front of the gas block, barrel can be no thicker than n). Potentially a year and a half wait time between 2 stamps, $400 in taxes, specific barrel, suppressor worth several hundreds, and most just say “F*ck it, I’m buying electronic muffs”

          • iksnilol

            True enough, though it isn’t dangerous to have a too thin barrel, as long as you have a shoulder (and one can be added to a barrel with some creative threading and machinework). Besides, that collar and whatnot is only for extra stability, otherwise you have just as little stabiltiy as you would with a muzzle mounted one.

  • JumpIf NotZero

    It’s an OK can. It’s the predecessor to the current Sufefire design. So if SF had never improved their can strength and the mounting system it would be this.

    I’ve broken an OPS mount/brake, and wasn’t impressed with the quality of the can… However, they were some of the first to make the design so freely flowing that despite it being louder at the muzzle than other cans, the backpressure on the AR was low and had little pop. The AT EAR noise we tested was on par with anything else but it felt nice to the shooter.

    There is a reason OPS never tested at the 1m/1m mic location, but effectively the can was good for the shooter.

    I have a SF on my Mk12-ish gun because I don’t see the point of clones and limiting yourself to the same bad choices that Crane had in the 90s.

    • Pete – TFB Writer

      Ron stands behind his work. He’d fix anything that needed it.

      • JumpIf NotZero

        I broke it back when OPS was still around. The bigger issue was where it broke – I’ve never seen any other brake break like that.

    • LanceCriminal86

      But that’s just the thing about “clones”, the context. In a history vacuum, they make as much practical sense as driving a 1950s Jaguar as your daily. Expensive, hard to find parts, no modern creature comforts. But in the context of collecting or dare I use the term “living history”, they provide a glimpse of like you said, what the best of 1998 to ~2006 had to offer. As soon as you step outside that box on a “Mk12 but not really” build, it defeats the entire purpose.

      Putting anything other than “period” glass or a can on a Mk12 build is like showing up to Pebble Beach with a ’53 Jag C-Type replica, but you put modern wheels and rubber as well as a stereo in it. Why copy any part of a Mk12, including the compromise 18″ barrel if you aren’t going to go 100%? You’re better off speccing out a 16″ free floated carbine with whatever rail, barrel, can, glass, stock, etc you want.

  • Rousso

    MK12 is an iconic rifle, but these iterations that are on display here are pervert.
    It’s supposed to look like this:

    • LanceCriminal86

      Owner of the title photo rifle. Original SPR/Mod 0 is best mod!

      I can also say that the others pictured are actually very faithful to actual, deployed Mk12s we’ve seen in use. Even the one with the honkin 3.5-15×50 Nightforce.

      • Pete – TFB Writer

        Thanks for coming by! And double thanks for the use of the picture of your awesome rifle.

      • Rousso

        That buttstock… looks so much LGBT, I can’t respond to that. I must be too homophobic. Seeing that makes me feel so uncomfortable.

  • Steve

    My AEM5 stamp cleared about 2 months back. Quietest can I own aside from .22LR stuff and AE has been a pleasure to deal with in answering the few technical questions I’ve had since purchase.

    • Pete – TFB Writer

      Surprisingly quiet.

  • Harry’s Holsters

    Awesome Story! Thanks for taking the time to get this in type.

  • A.P.

    I’ve always loved using my Mk12 Mod 1 clone. One of the most accurate rifles I’ve ever used; it has gotten me to Master Class in NRA/CMP Highpower, and is fun to shoot F/TR with at my local mid-range matches.

  • noob

    from US patent 4907488A which that silencer diagram is from
    “The spacing of the semispherical baffles is such that the discharge sound is raised to ultra sound.”

    Does this mean that if you had an ultrasound (or ultra high frequency tuned) microphone array set up with similar to the Raytheon Boomerang countersniper direction finder you could a sound suppressed weapon be easier to pinpoint using frequencies outside the range of human hearing?