At the time of this writing, as MK23 owners, we're pretty stuck for choice as to which nozzle we use in our pistol as no aftermarket replacement has yet to fall on our laps - and that's fine for now, after all, the nozzle does it's job pretty well and there isn't a whole load of reasons for it holding MK23 users back and for there need to be a new one... but... you can't blame us for leaving the door open to new innovations.

However, in the absence of a method to some how expand / improve the capacity of the nozzle, the nozzle port size and seal or even the jet of the nozzle tip, we are left with trying to find alternate means to increase the amount of propellant that travels out from the magazine, up through the nozzle and in to the barrel. If not for the pure FPS increase it would offer us, then for the extra efficiency of having a overvolumed system - especially in some of the more spruced up builds with longer / wider bore barrels.

Brother from another mother

Knowing that there is little we can do to change the size of the nozzle, we need to look at our MK23 much like an AEG by breaking down it's components to get a better idea of where we can improve it.

For the purpose of this article, we should assume the following for our MK23 components:

Magazine filled with a propellant: The AEG spring Magazine flow valve: The AEG cylinder. Magazine flow valve knocker pin: The AEG piston head. Pistol valve knocker: The AEG piston. Pistol trigger mech: The AEG gears and motor. Pistol nozzle: The AEG nozzle.

So with that analogy in mind, we want to increase the size of the cylinder and how much air it can store that can then be compressed and pushed out by the piston head and out through the nozzle and in to the barrel. To do this in our MK23, we need to look at the part that controls the amount of air that is let out of the magazine and up in to the nozzle, the magazine flow valve, and it's aftermarket upgrade: the Nine Ball Neo-R Flow Valve. You can learn more about cylinder volume ratios here.

Here's how it looks:

The packing is naturally pretty void of any English instructions, so we'll get to that later, but lets focus on what we can see. Firstly, the threading and size of this valve is only compatible with the Tokyo Marui magazine type flow valve threads - so clone magazine users looking for an upgrade, this is unfortunately not for you. Taking the part out from the package, the second thing we notice is that unlike the TM with it's thick spine and 4 ported holes around the valve chamber, the Neo-R valve opts for a single, larger port hole and thinner spine in the center of the valve chamber. Check them out next to each other.

What we can assume from looking at these images is that the Nine Ball will have less directional leakage than the TM as the single port only allows the gas to travel out one way instead of escaping from any of the 4 port holes that the TM has. With the single port and thinner spine, gas should be ejected immediately and in 1 constant directional flow; rather than being disrupted as it is trapped behind the valve and reaches the wall of the magazine housing, before finally having to push past the valve ports back through the center of the valve chamber out towards the port facing the nozzle. The image below better illustrates this explanation in the bottom panel, however the TM flow valve is as messy as it sounds.

In the image below you can see how the TM (left) and the Nine Ball (right) line up once install in the magazine housing. You can see that, at best, the TM can have 1 full port, or, half of 2 ports facing upwards towards the nozzle, depending how the valve is tightened.

The Nine Ball is able to have the full port facing upwards to the nozzle regardless of how the valve is tightened. This is where the Nine Ball really stands apart from the TM, as the entire valve chamber is able to freely rotate separately to the valve body and threads. This freedom of movement lets the user adjust the position of the port so that the full opening of the port faces up towards the gasket and nozzle, as seen in the images below.

Having the means to rotate the flow port gives the user direct control of flow permitted through the gasket, and therefore the eventual FPS per shot. This is a great feature for users looking for an alternate method of controlling their MK23's output where lower legal limits are required or a specific FPS is needed.

At this point, we can effectively say that the floodgates have been configured to allow for the maximum amount of pressurized flow to leave the magazine gas reservoir.

Unstoppable force vs immovable object

Having a fully functioning, super efficient floodgate is great, but also pretty useless if you can never get the gate open in the event of a flood. Just like the valve on a floodgate, there's a lot of pressure being held back behind that valve, and having too much pressure can become a problem, especially for our MK23's with their flow valve and the way they are designed to release the gas pressure in the magazine. To better understand the problem, let's look at some diagrams that explain the function of the flow valve in our magazine. In normal operation, upon trigger pull, the hammer strikes the valve knocker. The valve knocker then strikes the magazine flow external knocker pin with all of it's stored kinetic energy from the hammer strike. This kinetic energy is usually strong enough to de-compress the valve spring and move the knocker pin forward enough to disengage the seal at the other end of the pin inside the magazine reservoir, holding back all the stored gas pressure within the magazine. The seal is kept open long enough to allow a sufficient amount of gas through to propel the BB before the stored gas pressure and re-compressed valve spring forces the seal shut again from the inside, resetting the knocker pin in the same action and preventing the magazine from leaking out through the flow valve. We see this demonstrated in Diagram 1 below.

The success of the Diagram 1 operation is reliant on the kinetic energy of the hammer strike being greater than the kinetic energy of the stored gas pressure. If the force of the gas pressure pushing against the valve seal is stronger or equal to the force of the impact from the valve knocker, the valve knocker will fail to push the knocker pin far enough to open the seal and allow gas through. The gun will not fire as a result. We can see this in Diagram 2 below.

Now with that said, Laylax would clearly never release a product that would not be able function in normal operation without testing it. Unfortunately, their testing was in all likelihood conducted using HFC134a / Duster gas (or a propellant equivalent that kept the stock MK23 setup velocity under the Japanese legal limit of 1 Joule), and using such a gas meant that the valve knocker was always able to beat out stored gas pressure. Loading the magazine up with a much higher pressure gas (that would take the pistol well over the 1 Joule limit), such as propane, changes the function of the Neo valve considerably.

Have a look at the following image comparing a TM and Neo exterior valve knocker pin.

On the left, the TM valve knocker pin is clearly recessed in the magazine housing. On the right, the Neo valve is unnaturally seated outside of the magazine housing, by nearly 2 millimeters. This is not the Neo valves neutral position, without the gas, the knocker pin sits more recessed within the magazine housing, its only with the higher pressure gas does it sit so far out. We have chalked this down to higher pressure gas over compressing the seal and the flow valve spring, so that the knocker pin sits further out than it should on a lower pressure gas.

Whilst the knocker pin sitting further out than it should is not directly a issue, the amount of pressure pushing it out whilst using higher pressure gas is simply too much for the valve knocker to overcome, even attempting to push it in with a finger is noticeably hard. In addition to this, the valve knocker pin sitting further out also reduces the amount of travel that the valve knocker has to build up kinetic energy before impacting the valve knocker pin, only making it harder to fight the gas pressure.

During our testing using propane gas, it simply was not possible to engage the valve knocker pin using normal trigger operation, as demonstrated in the video below. For this reason, we cant not recommend that the Neo valve be used with any gas stronger than HFC 134a (Nuprol v1.0, Nuprol v2.0, Abbey Predator 144a), although your personal experiences may differ to greater success using anything with a stronger PSI. As a note, the stock TM flow valve operates without issue when using propane gas.