Last time, I did an unboxing review of the initial production run of the KSC Mk23 SOCOM Pistol CO2 ABS.
From what I've seen in reviews, the mechanism seems to be based on the classic 05HK, and it appears to employ a mechanical blowback unit, which is rare these days (most are vacuum-operated, and mechanical ones are only really common among manufacturers like WA).
It was a bit of a struggle to disassemble due to its unusual method, but I've finally managed to take the slide apart, so I'll show you how. At the time of disassembly, it had been fired approximately 300 rounds in a room.
We'll start with the field strip.
*This article aims to provide educational explanations from a mechanical engineering perspective regarding the safe hobby use of airsoft guns.
This does not promote acts of violence, the use of weapons, weapon modification, practical evaluation, or violation of laws and regulations.
Fieldstrip
KSC airsoft guns don't require you to remove the slide for hop-up adjustment, so you probably won't have many opportunities to field strip them. However, there might be times when you need to remove the slide for simple maintenance, so I'll explain it in a little more detail.
Pull the slide back slightly to align the groove on the slide with the slide stop lever.
In this state, push the slide stop lever from the opposite side of the photo and pull it out.
At this time, there is a clip attached to the slide stop lever, so be careful not to lose or damage it.
A detached slide stop lever will look like this:
Next, pull the slide forward to remove it.
That's it.
Back of the slide
The key point when assembling the slide is to insert the slide stop lever clip into the cross-shaped hole in the frame while attaching it.
Next, we will disassemble the components shown in the slide.
Recoil spring and barrel disassembly
First, we'll remove the recoil spring.
It appears to be a very simple recoil spring.
The spring is assembled with a C-clip at the tip.
If you want to change the spring, it seems you can easily replace it by removing the clip. I think changing the spring would be quite effective in increasing the blowback speed, but since the slide is made of ABS resin and is not very strong, I will leave it as is.
Next is the base of the recoil spring.
The outer barrel has a groove that secures it with a cam for short recoil and a slide stop lever.
Next, let's look at the outer barrel.
The outer barrel is made of ABS plastic. I would prefer it to be made of metal, so I hope that will be included in future custom parts.
Hop Mecha Club
Since the grooves on the hop dial are made of resin, you should be careful not to scratch them when adjusting the hop-up.
We'll now disassemble the outer barrel.
The outer barrel is secured with a grub screw and a locking mechanism that resembles a plastic slotted screw.
First, remove the grub screw.
These grub screws were unusual in Japan because they were made to inch standards.
Next, unlock the lock that has a slotted screw.
When you unlock it, the plunger and spring, which are part of the short recoil mechanism, will come out, so be careful not to lose them.
This part reminds me of KSC's incredibly elaborate mecha from the early 2000s.
Next, remove the inner barrel from the outer barrel.
Remove the clips that position the inner and outer barrels.
Remove the E-clip that positions the hop chamber.
Personally, I have weak grip strength, so I struggle to remove these kinds of clips. Using circlip pliers makes removing them much easier.
Snap ring pliers (also suitable for shaft holes)
Since clips are sometimes used, it's handy to have one on hand.
After removing the clip, shift the position of the drum part of the hop chamber.
During this process, be careful not to lose the steel ball that presses against the hop packing.
Remove the clip that provides the hop-up adjustment position and click feel.
All that's left is to remove the hop-up packing, and then the disassembly of the barrel area will be complete.
Let's take a look at some of the parts that caught my attention.
Hop chamber drum
The inside of the drum has a cam shape to push the steel ball (the ball pushes the packing, creating a hop).
Hop packing mouth shape
The lip has a shape that provides a strong grip on the bullet. The detailed reasons will be explained later, but since this model's blowback mechanism is mechanical, the function of this lip to firmly hold the bullet is important.
Hop's protrusion shape
The hop's protrusion shape wasn't quite a long-hanging hop, but it was a relatively long, bumpy shape.
Next is the inner barrel.
Inner barrel hop window
As expected from KSC, the machining is done with meticulous care.
Inner barrel tip
The tip is tapered and also has an O-ring for positioning.
The barrel appears to be made of brass (copper) with a painted surface. The barrel's inner diameter is probably 6.04mm.
Finally, here is a list of the parts around the barrel.
It has a considerably more complex mechanism and component configuration compared to typical gas blowback guns.
My guess is that KSC's SOCOM pistol from the 05HK era was released around 1997, and at that time, the hop-up mechanism hadn't been established yet, and various companies were still experimenting (Marui's hop-up mechanism was protected by a patent, and now that the patent has expired after 20 years, it can be copied).
In modern times, due to patent expirations and technological advancements, most manufacturers have adopted similar designs. However, KSC still uses a drum-type washing machine.
Given this background, and because this product has a unique hop-up mechanism, there are currently (early April 2023) very few aftermarket parts available for hop-up packing, inner barrels, etc., so we look forward to future developments.
From what I can see, the parts seem to be of pretty good quality, so if assembled carefully, you can expect decent accuracy and range (the looseness of the inner barrel's mounting is a bit worrying).
Disassembly of the blowback unit
We will now remove the blowback unit from the slide.
Remove the screw that secures the rear sight (this also secures the breech).
After removing the screws, remove the rear sight.
Next, remove the extractor.
Remove the grub screw that secures the extractor to the slide's rail.
Now you can remove the extractor.
This part contains a spring that operates the extractor, so be careful not to lose it.
Now you can remove the blowback unit.
This is the removed blowback unit (with the removed extractor attached).
side
back
Later
It's the exact same mechanism as the nostalgic 05HK.
We will measure the weight at this stage.
I think it falls into the lighter category in terms of weight.
We will now disassemble the blowback engine.
Remove the return spring.
Carefully remove the spring so as not to break it.
Next, remove the cylinder.
The cylinder can be removed by sliding it forward.
Next, remove the filling pin.
Remove the pins that secure the filing pins.
This pin is not press-fitted, so it can be easily removed with a pin punch.
Signet Pin Punch Set
It's not a luxury brand, but it's a recommended mid-range brand in the automotive industry that offers good value for money. Plus, it's inexpensive.
This will remove the firing pin.
Next, remove the piston.
First, remove the hexagonal bolt located deep inside the hole where the filing pin was inserted.
Now you can remove the piston unit.
I tried to disassemble the piston unit further, but it seemed to be assembled by press-fitting the parts together, so I gave up (it's impossible with the current equipment).
Now let's take a look at some of the parts that might interest us.
It's a cylinder.
In most standard gas blowback guns, the cylinder and nozzle are integrated, but this product uses a unique blowback system, so the nozzle is not attached to the cylinder.
The piston unit performs the function of the nozzle, so the piston passes through the cylinder.
The area where the piston passes through is sealed with a packing.
Back of the cylinder
The sticker is what you see in the background of the photo above.
Let's take a look at the gas route section of the cylinder.
Because high-pressure carbon dioxide is used, the holes in the gas route appear relatively small.
Next, let's look at the piston unit.
Almost all of the parts are machined, and they look expensive and highly precise. It's an unthinkable level of craftsmanship given the cost-consciousness of modern Japanese industry.
Looking at this part, I can feel the spirit of Japan as a manufacturing powerhouse in the late 1990s.
As a side note, if I recall correctly, KSC's 05HK unit used to be sold individually for around 3000 yen, but according to the instruction manual, the Pilton unit in this product costs 5500 yen (almost double).
From my perspective as a designer, this cost increase for mass-produced items seems quite reasonable, or even on the low side.
Since we're on the subject, let me briefly explain the operating mechanism of the piston unit.
This is the mechanism that fires the bullet before the blowback.
① The force of the bullet being held in place by the hop-up packing causes the first stage of the piston unit to be compressed by the bullet.
② When the tube retracts, the gas route to the bullet opens.
③ The gas pushes the bullet.
In reality, the three processes proceed simultaneously.
Because the bullet's retention force is important for pushing this tube to open the gas route to the firing side, the lip of the hop-up packing on this product is quite thick, as mentioned in the section on hop-up packing.
Next is switching the gas flow to the blowback side.
① The bullet is fired, the retainer on the piston unit's barrel is released, and the barrel extends.
② The extension of the tube closes the gas route to the firing side.
③ Gas flows to the blowback side.
In reality, the three processes proceed simultaneously.
This method, which uses the bullet itself to switch the gas route rather than the typical negative pressure differential, is sometimes called a mechanical system. It seems that WA is one of the few companies still using this method.
The advantages include the fact that the bullet firing and blowback processes are completely separate, so the blowback starts only after the bullet is released, just like in a real gun. This generally results in better accuracy and better fuel efficiency.
However, in my personal opinion, vacuum-operated systems have also evolved considerably, and I feel that there is almost no difference in performance, or that vacuum-operated systems are slightly more advanced.
Keeping the mechanisms explained so far in mind, watching the next video showing the piston's movement will deepen your understanding.
KSC Mk23 SOCOM Pistol CO2 Piston Movement Video
There's an article explaining the general negative pressure mechanism, so please take a look if you're interested.
This completes the disassembly of the blowback unit.
Blowback parts list
Since we're here, let's take a look at the empty slides.
Back of the slide
This particular unit had fired around 300 rounds, but there was no noticeable damage to the slide.
If it were clearly lacking in strength and breaking, damage would appear after firing fewer than 50 shots, but since no damage is apparent, there doesn't seem to be much to worry about (single-shot destruction and fatigue failure).
I think it's fine because, despite being a CO2 model, the slide movement is comparable to the HFC-134a model.
Next up is the slide notch, which is of particular interest.
There's a slight crushing visible, but it seems to be holding up reasonably well for a KSC ABS model. On some models, this part breaks off after just one use, so it appears to have decent durability.
However, a major factor might be that I rarely use the slide stop lever to return the slide, as described in the instruction manual.
This completes the disassembly of the slide.
Summary
The complex component configuration reminded me of the old KSC products.
Disassembly isn't too difficult, but there are a lot of parts. The mechanism is exactly the same as the old 05HK.
It's an interesting phenomenon that a mechanism that previously couldn't function properly under HFC-134a pressure is now working again under CO2 pressure, and I'm looking forward to seeing what happens next.
One of the biggest advantages is probably the exceptionally high level of machining and assembly precision, likely due to production at their own domestic factory.
Although it has only fired 300 rounds, looking at the disassembled parts, there are no areas that appear to be severely damaged, suggesting that it has a decent level of durability.
On the other hand, one thing that bothered me, which is common with KSC products, was that there was hardly any grease applied to the moving parts.
From my perspective as a mechanical designer, I believe that basically no moving part can be dry, so I will take measures to address this (excluding special surface treatments such as Teflon coating).
I'm also concerned that the shape of the cylinder holes and the gas route holes in the piston don't match.
Therefore, the points to be adjusted going forward are as follows:
- Additional machining of the inner barrel window (something I always do)
- Polishing and greasing of each sliding part
- Machining of holes in the piston unit
Thank you for your time.
Next time, we'll be disassembling the chassis.
KSC Mk23 SOCOM Pistol CO2 ABS
This is the only gas blowback model of the SOCOM, and I highly recommend it.
KSC Mk23 SOCOM Pistol CO2 27-round Spare Magazine
Up until now, obtaining spare magazines from KSC was quite difficult (past tense). The future is uncertain.
KSC Genuine CO2 12g Cartridges (50-pack)
If you don't have any particular preferences, this isn't the only option (the price is a bit on the higher side). While 50 bottles might seem like a lot, they'll run out quickly. At your own risk, you might be better off with something cheaper.
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