The Suppressor


Design I

Anduril is designed specifically to incorporate a suppressor in its operation. Indeed, in some locals (Washington State for example) a Suppressor is allowed but a SBR is not. The stock weapon/cartridge platform is specifically designed for a barrel length of 10 inches, a length necessary to extract 98+% of the cartridge energy from the 10mm. In locals where an SBR is allowed, a short suppressor can be screwed on the end and removed for cleaning. In a local not allowing SBR’s, a Suppressor of sufficient length can be screwed onto the end of the barrel and permanently affixed to the barrel (according to BATF Regulations) so as to render the Overall length of the barrel at least 16 inches. Silver soldering, welding, pinning etc may have to be used to meet this regulatory burden. Until a Tax Stamp can be obtained for the Suppressor, a false suppressor can be used to get the feel and the balance of the weapon. One’s like this by MFI:


This false suppressor attaches via a sleeve adapter which screws to the barrel via a threaded end; the barrel in this case being 16 inches (to make it a carbine) or with a permanently attached false suppressor to a shorter barrel to make it at least 16 inches, therefore also a carbine.

If using a real suppressor, it is important that the paperwork be carefully retained so as to prevent the BATF from destroying your life. Also, since the suppressor can not be removed, then it is important that it be able to be cleaned and maintained while in place on the weapon barrel.

Design II

Rather than just screw a “can” on the end of the barrel I decided to take a page from our Grandfathers and make the suppressor and barrel as one. It cuts down on tax stamps and will allow a standard Sub-sonic load to be developed that will cross platform lines by bleeding gas from the barrel starting at the 10 inch mark (point of max velocity).

The design I picked was the famous anti-Sentry weapon called the De lisle carbine from WWII.


The only change is that I have set the suppressor to bleed gas under the barrel towards the back. The holes in the barrel are in the middle rather than at the beginning of the barrel as in the De Lisle (pronounced De-Lyle)  so gas is diverted at the middle as well as towards the front like screw on cans. The barrel in nominally 16 inches, but in reality it only generates acceleration like a 12 inch barrel due to pressure being bled off long before the bullet exits the barrel. An additional endcap extension can be added to reduce any “pop” caused by standard configuration.

See original De lisle suppressor below:

Enfield De Lisle Carbine CanThe ports are in the middle which allows the gas (and noise) to go in many directions at once. The original De Lisle was so quiet that the bolt action itself was louder than the shot. 10mm subsonic ammo with 220 grain lead bullets or 200 grain jacketed bullets would be just as quiet. On the other hand ALL shots from this weapon, whether full auto, semi-auto or single shot would be suppressed.

The Suppressor and the barrel will be one unit and will vibrate together. The suppressor’s endcap will screw onto the end of the barrel. The body of the suppressor is Titanium for both strength and light weight with an advanced, noncorrosive titanium structure on the interior. The De Lisle’s main body was steel and quite heavy. The endcap will be unscrewable for cleaning only from the front and the main body will be removable but the barrel will be 16″ to keep the overall length at Gov regulation. The interior will have to be cleaned with brushes inserted from the front.

By using an updated,  known design, I can spend money on the materials rather than design and research. Though the Katana will NOT be as quiet as the De Lisle Carbine with the supersonic ammo,  it WILL be as quiet using the 220 grain subsonic loads or 200 grain FMJ loads set up  strictly for accuracy and with advanced materials, be as nearly maintenance free as possible. Moreover, when the design is finalized, all of the Katanas can use a 16 inch barrel, though the gas will be ported off at about 12 inches or so, but even with power improvements, this design will hold steady while extracting 98% of the energy from the bullet, while allowing for a suppressed shot.  A version with a shorter barrel (12 to 14 inches) can be tested for military applications with a recessed muzzle (inside the can) but I doubt it will get significantly quieter. The idea of the recessed muzzle is to try to eliminate the “pop” of the bullet leaving the barrel, but if the suppressor holes in the barrel are large enough, such a pop should be tiny and an odd setup will be unnecessary.

Perfect for quiet hunting or taking out looters.

The De Lisle carbine in action:


ALL ITEMS DESCRIBED and their sources will be placed on a “Sources” page so that “Andurils” can be duplicated.

Design III

Update! Purchased a MFI fake Suppressor for a straight wall barrel as I will be ordering my barrel in 16mm (0.630) O.D. and the interior of the Universal unit is (0.640). Unit arrived in two days (thank you MFI). The unit is EXACTLY on spec, with perfect machine work and simply no flaws whatsoever. no fuss, no changes, no needing to “tweak” anything. It is a copy of the Knights Armament SOCOM unit. I plan on putting a shallow ring on the barrel where the set screws touch so the unit is locked to the barrel. Weight is exactly right on to a real suppressor.What a nice unit.


Beautiful workmanship

With holes drilled into the barrel, the real suppressor will start taking gas from the 10 inch mark, which is just forward of the 4 knurled rings with holes starting right about where the first divot is in the picture above. These holes in the barrel get progressively larger to the end of the barrel.  When the unit is removed, the barrel will still be 16 inches, thus legally a carbine. The end of the barrel can still be threaded if you so desire as a thread protector can be added. (Also the fake suppressor acts as a thread protector). Barrel with holes alone and no suppressor body will act as a integral “Muzzlebrake”.



2 Responses to The Suppressor

  1. Michael Frost says:

    This is Michael with MFI… While I appreciate your imagination and ingenuity you need to be care not to run a muck of the law as well as create what I view as a likely hazard to your health and perhaps life. Fist of all ATF is very clear about “creating an expansion chamber” as you are describing by drilling holes in your barrel and then covering them with something like our barrel shroud. I doubt that it would drop the noise level below the ATF decibel threshold, but then that begs the question as “why are you doing this in the first place”… that gets into the intent issue.

    More importantly the product you are using is NOT designed to take any pressure at all much less that from a ported barrel. I am reasonably sure that this application would result in fragmentation of the SOCOM Shroud and result in serious injury and even death to you and those around you.


    • Dear Michael,

      Thank you for your comment. I agree, nothing mentioned here on this website is an advocation of breaking Federal law concerning the manufacturing of controlled items under the NFA or any other law. Further, such studies are merely mental exercises on the part of the author, NOT tested designs. MFI fake suppressors are merely used as examples of real suppressors and should not be modified in any way, nor is this author advocating doing so.


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