LAYLAX SIGSAUER M17 CO2 GBB Slide Disassembly (P320)

In the previous post, I gave a general overview of my review of the LAYLAX SIGAIR Proforce M17 CO2 GBB.

This time, we'll be disassembling it. As we go, we'll also be considering the assembly process, design philosophy, and manufacturing methods.

Fieldstrip

We will remove the slides.

With the slide open, lowering the takedown lever will release the slide forward.

This is a detached slide.

At first glance, it's clear that a lot of ingenuity has gone into it; the blowback engine protrudes from the slide in order to increase the diameter of the blowback cylinder.

You can see it clearly when you look at it from directly to the side.

It's an amazing design. I think this is what creates that incredible sharpness.

Since we're at it, let's weigh the entire slide assembly.

At 224.5g, it's quite heavy, easily exceeding the average bolt weight of 200g for a gas blowback M4. The fact that it works so smoothly shows just how powerful CO2 is.

Let's take a look at the recoil spring.

It looks pretty standard, but the only distinctive feature is the serrations (gear-like components) for adjusting the hop-up.

Now we'll start disassembling the components within the slide.

Disassembly of the barrel

Let's take a look at the outer barrel.

It has a mysterious O-ring attached. I thought it might be for shock absorption, but when I fitted it to the slide, there was no place for the ring to make contact, so I wasn't sure what it was for.

Next, we'll turn it upside down and examine it in detail.

A cam is included to simulate the barrel tilting mechanism. This allows the outer barrel to move.

Let's take a look at hops.

First, let's look at the hop adjustment setting at 0.

There are absolutely no protrusions. It's no wonder the bullets sometimes fall out.

Hop adjustment is at maximum.

The amount of protrusion is small; countermeasures are needed.

Next, we will disassemble it.

Remove the hop-up chamber from the outer barrel. To do this, first remove the spring, which is often overlooked.

This spring only needs to be detached and placed in place. Its function is to pull the outer barrel back from a tilted-up position to its normal position.

Next, remove the pins at the locations shown in the photo.

This is extremely hard, so I recommend using a sturdy pin punch.

Once removed, the hop-up chamber can be taken out of the outer barrel.

The pin was slightly bent. It was probably bent from the start. I'll straighten it later.

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.

Eagle Force Maintenance Bench Block for Handguns
It's incredibly convenient to have. Moreover, it's designed for handguns but can also handle longer firearms, making it very useful. In fact, I personally didn't see the need for their M4 version.

Vessel Plastic Hammer
It's inexpensive, sturdy, and long-lasting. For a good balance of control and power, the 1-pound size is recommended.

Here are the parts we've disassembled so far.

Next, we will disassemble the hop chamber.

Remove the two screws shown in the picture.

Disassemble the chamber. Be careful when disassembling it, as the internal parts may come loose if not done carefully.

Now I understand why the BBs were falling out and the hop-up was weak.

With the hop adjustment at 0, there is a gap between the hop arm and the packing. This means that unless you turn the hop dial a little, there will be no hop at all, the BB will not be held in place, and any adjustment you make will be wasted because of this gap.

This also requires countermeasures.

Next, let's look at the components inside the chamber.

These are serrations for adjusting the hop-up (they're like gears).

One of the O-rings had fallen off during assembly. That's a shame. Here's a photo after reassembly. Incidentally, I believe this O-ring is there to provide a slight resistance and prevent slippage during hop-up adjustment.

Next is the hop arm.

This is a sheet metal plate that has been punched out. The part that presses the hop is long-range, so I think it will improve considerably if it is adjusted properly.

Next is the gasket.

This is a long-contact type packing, commonly found in genuine VFC parts. It performed well on the UMAREX/VFC G45 and GLOCK 19X, which I've introduced before.

Finally, there's the barrel.

This is a hop window.

This is a hop window that appears wider than the so-called wide type. The processing here was done well, with few burrs.

This is the tip of the barrel.

It's a straight barrel with no taper.

The barrel appears to be made of aluminum. I don't think it's a particularly bad barrel.

Disassembly of a blowback engine

Now we'll disassemble the blowback engine. First, let's take a look at the blowback engine.

Let's try moving the nozzle (the black part).

It extends quite a bit. This likely indicates a fairly long slide stroke.

Let's take it apart.

Remove the screws shown in the picture.

Removing this screw will detach the blowback engine along with the covers for the rear sight and red dot sight mounts on the top of the slide.

This is a cover for the red dot sight mount.

Similarly, the blowback engine can be easily removed from the slide.

Removing it reveals the blowback engine (piston cup, loading nozzle).

Removing the screws shown in the next picture will allow you to disassemble the loading nozzle and piston cup.

Let's take a look at the disassembled piston cup.

It has a rather unique shape in order to maximize surface area within a limited space. A piston cup is usually circular with a diameter of 13-15mm. The larger the surface area, the more gas pressure it can receive, resulting in a stronger blowback.

The "impressive 15mm cylinder diameter" often mentioned in the marketing of GBBs, or the "15mm" in System 7, refers to this diameter. Incidentally, the reason many cylinders are circular is because a circular shape makes it easier to seal the gas, thus preventing gas leaks.

With a special design, it's possible to prevent leaks even with a product of this shape, so it depends on how you approach it.

Given the shape of this product, the surface area appears to be larger than the 15mm diameter rim, resulting in a considerably strong blowback.

I've also explained the operating mechanism of gas blowback guns, so please take a look if you're interested.

Let's take a closer look at the piston cup.

View from above.

View from below.

There are quite a few burrs overall, so I will polish them down during the customization process.

Next, let's look at the nozzle (loading nozzle).

By the way, the nozzle is shown upside down.

It's to the side.

The opposite side.

This is the back side.

You can see a floating valve in the middle.

I would also like to show you a photo of the nozzle from the front, but I forgot to take one by itself, so this is a photo of it assembled into the slide.

The nozzle's gas outlet area has likely been significantly reduced to lower the initial velocity. As a result, the initial velocity is relatively low for a CO2-powered gun.

The complete set of parts that have been disassembled so far looks like the following picture.

This post has gotten quite long, so I'll stop here for now. Next time, I'll cover disassembling the nozzle, disassembling the chassis, summarizing the process, and setting custom goals.

LAYLAX SIGAIR Proforce M17 CO2 GBB Coyote Brown
It's a good product despite some shortcomings. Furthermore, it's valuable because this is the only model officially adopted by the US military.

LAYLAX SIGAIR Proforce M17 CO2 GBB Spare Magazine
Since it's from LAYLAX, I think the supply will be stable, but given the current situation, there might not be any ships available, so I recommend buying while you can.

LAYLAX High Bullet CO2 Gas 6-Pack
Six bottles will probably be gone in no time, but I'll introduce them anyway.

LAYLAX High Bullet CO2 Gas 30-Pack
Since you'll be using them anyway, I recommend the 30-pack, which is cheaper. It's under 3000 yen, so it's a good deal.

Marushin CO2 Gas, 30-pack
It's probably usable. I think Marushin offers the best balance of price and quality.