You may be thinking that the propane fumes have finally gotten to our heads, but it's true, you can make the MK23 even more deadly and quiet by adding one simple modification to it's suppressor.

Lovingly coined as "The Fart Flap" or "The Sphincter" by some, this modification (apparently) adopts it's name for the visual, audible and functional likeness to the body part of the same name. However, there is little biology involved in the modification itself, rather, the only sphincter affected by this article is that of the opponents as it goes through an involuntary clench as they receive a round from your "fart flapped" pistol a couple of feet away.

What you're seeing in the image above are several suppressors that have been modified with a "Fart Flap". The modification is incredibly easy to install on your suppressor and is just as affordable. By using a strip of fabric or a fabric based adhesive backed tape (camo tape being one of the most useful options for a woodland player for obvious reasons), a MK23 user can seal over the end of the suppressor to create an airtight chamber within the suppressor. Once sealed over, a small cross section is cut through the muzzle hole with a razor blade, or, more brutally, a hole in the tape can be made by firing several BB's through the tape to get an exact exit (wound) hole. This basically allows the BB's to pass through the fabric tape, but helps keep excess noise trapped within the suppressor itself as the fabric closes back in on itself.

If it works, it ain't stupid

The idea was inspired by information gleaned from Wikipedia articles whilst researching real steel suppression, and is drawn from the "wet suppressor" design that utilizes rubber discs throughout the suppressor that the round punches through. The real steel items are only useful for one covert mission before they require replacement, however our airsoft variants will last several fun filled weekends of silent but deadly play; and can easily be maintained with replacement tape. Another real world design that follows the same principle (albeit it with liquid rather than gas) is a liquid food valve, which opens when pressurized liquid is forced against it, and then closes when the pressure is retracted. You can see some examples of this in the images below (note the "X" shaped exit hole and how it extrudes forward when pressure is applied).

Flatulence in motion

A while back when we first experimented with this mod before testing it for many months to ensure it's applicability so that we could present it to you here, we recorded a quick clip that captured the fart flap in motion and how the fabric tape would extend forward to allow the BB and air pressure to pass through, just like the liquid food valve example above. We applied the flap to a much larger suppressor, just to prove that it's effectiveness was not limited to the stock MK23 suppressor. Check it out here below.

Now that you know the science and purpose behind the fart flap modification, let's take a quick look at one way to perform the modification to your suppressor (we say one way, as there are likely several more eloquent and neater ways to do it).

Flaps engaged!

To start off, you'll need your fabric, or adhesive backed fabric tape (this is the kind we reccomend: Link). You'll also need a blade, razor or scissors and of course your selected suppressor. For the purpose of the installation, please refer to the images in the gallery below the instruction steps.

1. Start off by cutting off a length of your fabric tape that fully covers the surface of the suppressor muzzle and end cap.

2. Place the fabric directly center over the muzzle hole and ensure a secure fit (see image FF1).

3. Cut the surrounding excess fabric in to sectioned tabs (see image FF2).

4. Secure the tabs down to the side of the suppressor.

5. Cut a new length of tape and wrap it around the side of the suppressor, covering and securing the flap tabs (see image FF3).

6. With the muzzle fabric secured, find the edge of the muzzle hole beneath the tape (you should be able to feel it).

7. Taking your blade, start at the edge of the muzzle hole and make a straight cut directly across to the opposite side of the muzzle hole.

8. Locate the opposite muzzle hole edge of where you made your first cut and repeat a straight cut across the muzzle hole.

9. This should result in a "+" or "x" shaped opening. (see image FF4).

10. With your opening made, go over the cuts again and make sure the full length of the muzzle hole is covered from end to end of the "x".

With your suppressor successfully fart flapped, you're ready to start putting some rounds through it and hearing the result for yourself!

For MK23 users that use Propane or MAP/P gas, you're unfortunately still going to get the usual unpleasant smell every time air escapes the fart flap, one could suppose it's just more appropriate this way.

When first using the fart flap, you may notice that shot accuracy is effected but after a couple of mags you should see normal accuracy return as the fabric is worn in. Another thing to consider if you opted to use adhesive backed tape is the adhesive side of the tape where the suppressors original muzzle hole is covered. You can either leave this to bed so it loses its adhesion or coat it with something like silicone oil or talcom powder to reduce the drag on the BB's as it passes through. Alternatively, if you are using a thin enough fabric tape, simply double side the part of the tape that covers the muzzle hole so that the adhesive side is not exposed to the BB. Your fart flap should look a little rough around the edges after a while, like in the examples below.

Fart over form?

In summary, we know know that this is not the most attractive mod out there, and it would definitely kill off the aesthetics of a B&T Rotex suppressor if applied to it; but the function and simplicity of the fart flap is undeniably useful and well worth using in the right hands, but you should consider the following points first before you go ahead with it:

- For users that find themselves getting up close to the enemy team, this is definitely a modification that deserves testing. S̶e̶e̶i̶n̶g̶ Hearing really is believing.

- For those that have the MK23 in a carbine kit running at DMR power, whose engagement is more like a long distance romance then it would it be for you? Maybe not, as the low risk of affected long range accuracy is still a risk to consider, but absolutely for a sidearm user.

This is one of those modifications that is easily reversible and non destructive; so why not give the Fart Flap a go and get those sphincters twitching?

Personally, I've had Fart Flaps implemented and in use for nearly ten years on various weapon platforms and will always have one in use on my MK23 sidearm. If you need further inspiration, check out Kicking Mustang's live stream demonstrating the Fart Flap, here.

We hope you find this mod helpful and enjoy the newfound awe from your opponents as they hear it for the first time!