LAYLAX SIGSAUER M17 CO2 GBB Custom Part 1 (P320)

In the previous articles, I summarized the disassembly and improvements of the LAYLAX SIGAIR Proforce M17 CO2 GBB.

This time, we'll address the areas for improvement we discussed last time through customization.

Let's review and decide on areas for improvement and methods for modification.

Improvements and modification methods

Let's review and list the areas for improvement.

I considered some possible methods for renovating this area.

We will proceed with this.

With this project, it looks like I'll be able to complete it through fabrication without using any aftermarket parts.

We will now proceed with the actual customization.

Customization of hammer, trigger, and chassis

In the disassembly section, we didn't disassemble the hammer unit, but we decided to disassemble it to improve the safety.

I thought the safety was held in place by a grub screw, so I tried removing the screw.

Other side

I removed the grub screw, but I couldn't disassemble the safety mechanism (I later found out it's press-fitted). So, I decided to repeatedly move the safety mechanism to break it in.

I'll give up on the safety modifications right away and move on to the next thing.

Remove the trigger spring shown in the picture. Be careful not to let the spring fly off while you work.

Removing the spring frees up the trigger bar.

This explains the poor trigger feel. The contact surface between the trigger bar and the hammer unit is rough (poor surface finish).

Furthermore, there are marks from the push pins used during casting on the contact surface between the bar and the unit, which is not good.

This is the trigger bar.

I'll buff this with a rotary tool.

This is after polishing.

unit.

Trigger bar

If you polish it too much, the dimensions will change and it will no longer be able to perform its original function, so I'll stop at a reasonable point.

Dremel High-Speed ​​Rotary 4000
This is my go-to rotary tool that I always use. Having this expands the possibilities of your DIY projects. There are two popular models, the 3000 and the 4000, but I recommend the 4000 because it comes with a set of tools and has more power.

Next, I assemble it while applying the usual Bellhammer No. 0.2 Gold Grease to all the movable parts.

Near the knocker return.

Near the hammer unit.

Near the trigger bar.

We'll now assemble this into the frame. It's easy; just reverse the disassembly process.

All that's left is to insert the takedown pin and you're done.

Bellhammer No. 2 Gold Grease
This is a classic, top-quality grease. No. 2 has the same ingredients as No. 0 but with a higher viscosity. I primarily use it for metal-to-metal connections.

Next, we'll customize the hop-up chamber area.

Hop chamber, inner barrel

Let's take a look at the hop-up window on the inner barrel.

It's not a bad inner barrel, but due to the manufacturing process, any barrel will have edges and burrs around the hop-up window.

This edge is filed down with a round diamond file.

All that's left is to clean the inside of the barrel, and you're done.

Diamond file set
These diamond files offer great value for money. The round files, in particular, are very useful. The 5-piece set is highly recommended.

Next, we'll assemble the hop packing.

The original hop-up packing has a long-range shape and just the right hardness, so I'll use it as is.

The assembly method is a well-known one: first, apply silicone grease to the inner barrel.

Carefully assemble the gasket and use standard sealing tape to ensure airtightness.

The barrel is now complete.

AZ Silicone Grease
This is a standard product from AZ. While Tokyo Marui's genuine grease is sufficient, the quantity is small, so AZ is recommended. It's also inexpensive.

KAKUDAI Seal Tape
This is a standard item for ensuring airtightness in all kinds of applications and can be used not only with airsoft guns but also with other items.

We will now temporarily assemble this into the chamber.

As I found during disassembly, there is a gap between the packing and the hop-up arm, so I will fill it in.

The method is simple: attach a plastic plate to the part of the arm that presses against the packing.

I tried attaching a 0.2mm plastic sheet as a test.

We'll temporarily assemble this into the chamber and check the hop strength.

The hop was a little too strong with the 0.2mm thickness, so I adjusted it by sanding down the attached plastic sheet.

The ideal thickness for my sample was 0.66mm.

I think there's a lot of individual variation in this area, so it's something that requires some negotiation.

Tamiya plastic sheet, 0.2mm thick
There's no particular reason, but I use Tamiya plastic sheets. 0.2mm is a convenient thickness for filling small gaps and adjusting thickness.

Next, we'll carefully assemble the hop-up adjustment parts.

The O-rings for the adjustment serrations were installed incorrectly, so I'll fix that.

Since these parts are made of resin, we'll assemble them while applying Bellhammer No. 0 Gold Grease.

Bellhammer No. 0 Gold Grease
This is a classic, top-quality grease. No. 0 is a low-viscosity grease. I generally use No. 0 for resin-to-resistance and resin-to-metal connections.

Now, we'll assemble it carefully.

Before putting the cover on, make sure to install the spring that tilts up the outer barrel.

Here, we'll check the protrusion of the hop for confirmation.

It's coming straight down, so that's okay.

All that's left is to assemble the outer barrel and you're done.

The hop chamber is now complete.

Next, we will polish the slides.

Polishing and adjustment of slide rails

First, let's look at the slide rails.

It's not visible in the photos, but if you touch it with your fingertips, you can feel the edges and burrs.

This isn't the manufacturer's fault; it's unavoidable that burrs, edges, and press marks will appear when manufacturing with sheet metal presses. While it would be possible to add a deburring process to increase costs, this would raise the price, so it's often left as is to strike a balance.

However, since it is inevitable that sheet metal pressing will result in press sagging, burrs, and sharp edges, designers will devise ways to ensure that these issues do not affect the function or performance of the sheet metal.

Leaving that aside, I'll apply the usual buffing to the rail section.

Dremel High-Speed ​​Rotary 4000
This is my go-to rotary tool that I always use. Having this expands the possibilities of your DIY projects. There are two popular models, the 3000 and the 4000, but I recommend the 4000 because it comes with a set of tools and has more power.

These are the slide rails after polishing.

The polished slide is temporarily assembled into the frame, and its smoothness is checked by moving the slide.

One important point to note here is that if you have already assembled the hammer unit into the frame, it is best not to move the slide back any further than the position shown in the photo.

The knocker return mechanism can cause the hammer to get caught on the slide, preventing it from being removed. Please be careful.

The slide adjustments are now complete.

This is getting a bit long, so I'll cover the rest and summarize in the next post. Please check it out if you're interested.

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.