BATON BM-45 CO2 GBB FDE 3rd Lot Customization Completed

In the previous customization episode, the frame was completed.

The direction of the customization we decided on last time is as follows:

With that in mind, we will now customize the remaining slide section.

Custom slides

First, before assembling the slide components, we will perform a fitting test between the completed chassis and the slide.

Let's try assembling the slide, which has no parts assembled yet, into the completed chassis and see if it works.

There's a slight resistance, so I'll file down the next photo section (both sides) of the slide.

The method for sanding is the usual Dremel rotary tool with a buffing attachment.

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.

This slide is made of nylon resin and is quite hard, so it's difficult to file, but I'll do my best to file it down.

I file, assemble, check the fit, and finish when I'm satisfied.

Nozzle, bleach

Next, we'll assemble the nozzle.

The components of the nozzle are as follows:

There may be differing opinions on this part, but I apply a thin layer of grease (Bellhammer Gold Grease No. 0) before assembling it.

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.

Next, let's take a look at Bleach.

Since the piston cup wasn't disassembled during the breech disassembly process, we'll remove it now.

The bottom of this breech comes into contact with the chassis's hammer unit, so we'll modify the bottom to improve its sliding properties (buffing with a Dremel rotary tool).

My personal guideline for the amount of modification was to remove the black paint.

One important point to note here is that the grooves in the breech are used for timing control of the hammer unit, so do not modify them (gas cut timing).

The assembly order is a bit out of sequence, but I'll explain it at this stage because I encountered a problem related to the breech.

The problem was that the slide did not fully return during blowback.

Let's take a closer look at the location where this phenomenon occurred.

A closer look at the issue reveals that the hammer and breech appear to be interfering with each other as the slide returns.

There seem to be two possible causes.

Since we fixed cause 1 in the previous assembly, we will consider that issue resolved and proceed to implement the countermeasures for cause 2.

First, let's take another look at Bleach.

We'll use a rotary tool to grind down the corners of the area circled in red in the photo above.

The desired finish is a smooth, sloping shape.

This completes the countermeasures.

Next, we'll attach the nozzle to the bleach.

Since the nozzle part is also movable, I'll apply Bellhammer Gold Grease No. 0 to it.

Finally, install the nozzle return spring and you're done.

Incorporate this into your slides and you're done.

Chamber, barrel

Next, we'll assemble the chamber section.

First up is the barrel.

I personally didn't like the shape of the stock hop-up window on the barrel, so I'm changing it to an aftermarket part, the Maple Leaf Crazy Jet barrel, with an inner diameter of 6.04mm (the stock inner diameter is 6.05mm) and a length of 110mm.

Maple Leaf Crazy Jet Barrel, Inner Diameter 6.04mm, Length 113mm
Personally, this is a parts manufacturer I frequently use for gas blowback airsoft guns.

I'm not entirely convinced by the "increased range through airflow" claim on this barrel, but I like the finish and the shape of the hop-up window, so I use it often.

Let's compare the original barrel and the hop-up window (Maple Leaf on the left, original on the right).

The top one is Maple Leaf, the bottom one is the original.

You can clearly see that the shape of the hop window is different.

Next, we'll attach the hop packing to this.

Apply silicone grease to the hop-up packing mounting area of ​​the inner barrel (to improve airtightness).

While Tokyo Marui's genuine silicone grease is fine, the quantity is small and it's not cost-effective, so I use AZ brand silicone grease.

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.

Attach the hop-up packing to the barrel and wrap it with one layer of sealing tape to complete the process (improves airtightness).

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.

The barrel is now complete.

Next, we'll customize the hop-up arm.

Now, we'll modify the hop-up amount to strengthen the customization direction we summarized at the beginning of the previous article (to prevent BBs from falling out when the hop-up is at 0).

To increase the amount of hop-up, you simply need to increase the amount you push it in, so we'll put a cover over the part of the hop-up arm that contacts the hop-up packing.

Normally I would use plastic sheets or something similar, but the contact points on this model are curved, not flat, making it troublesome to use plastic sheets, so I'll use heat shrink tubing instead.

If you use a tube that's too large in diameter, it will be too loose, so I used a tube with a moderately sized inner diameter of 5.2mm.

Once molded, it will look like the following picture.

That's it.

These parts are then assembled into the chamber, and the process is complete.

Here, I'm applying Bellhammer Gold Grease No. 2 to make the hop dial easier to move.

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.

Finally, attach the outer barrel to the chamber and you're done.

Embedding into slides

First, before installing the outer barrel into the slide, apply grease to the shaded area in the following photo.

Although this model doesn't have short recoil, the slide and outer barrel still slide against each other, so I'll apply some grease just to be safe.

Next, install the outer barrel and you're done.

Before installing the slide into the chassis, apply grease to the shaded area in the photo above.

Next, before installing the slide into the chassis, apply grease to the rail section of the chassis.

Now, just add the slides and it's complete.

For detailed instructions on how to assemble, please refer to the disassembly section.

I've included an explanation of the gas blowback mechanism for reference. Please take a look if you're interested.

Live-fire performance verification

We will check the shooting performance after customization.

The conditions were a CO2 cylinder (LAYLAX product), a magazine surface temperature of 26.6°C, and a room temperature of 6°C, with 15 rounds loaded (G&G bio BBs 0.2g).

Normally, measurements are taken under conditions of 20-25°C, but on the day of the measurement, a severe cold wave occurred, and the room temperature did not rise easily, resulting in measurements being taken under unfavorable conditions of 6°C.

This is a measurement of the initial velocity with the hop-up adjustment set to 0.

Out of the box, the BBs were misfiring and measurement was impossible, but now it has achieved a muzzle velocity of 81.6 m/s, so the problem has been solved.

Next, let's multiply the hops by about $ \frac{1}{3}$.

It turned out quite well.

Introduction article on chronographs

Fuel efficiency

Next is fuel efficiency.

This is the weight of the magazine before firing.

The weight fluctuates slightly between 200.5g and 201g, so I'll use 200.75g (the scale has 0.5g increments).

This is the magazine weight after firing 15 rounds for measurement.

15 shots were fired using 2.25g of gas, which works out to 0.15g per shot. Out of the box, the gas consumption was 0.1g per shot, which seems to have worsened, but the measurement was taken at a room temperature of 24°C, and this time it was at 6°C, so I think it has improved (even carbon dioxide gas consumption varies considerably with temperature).

According to research, a CO2 cylinder holds 12±1g, which should allow for about 80 shots (5 magazines). However, to maintain the necessary gas pressure for firing, it would probably only be enough for about 4-5 magazines (at room temperature of 6°C).

Finally, here's a video of it in operation (room temperature is 6°C).

Baton BM-45 CO2 GBB Custom Unit Operation

This video shows the gun in operation after firing three magazines' worth of rounds (45 rounds). Considering it was operating at a room temperature of 6°C, I think it performs quite well.

In terms of actual shooting performance, out of the box, with the hop-up adjustment set to 0, the BBs would fall out of the sights, but now with 0.2g BBs, the muzzle velocity is 81.6m/s, making it perfectly usable, so I'll consider the issue resolved.

G&G Bio-Bullets 0.2g
It's inexpensive and accurate, so I use it for a wide range of purposes, from performance testing to airsoft games. It's been my favorite since it first came to Japan (around 2008). It lasts a long time for a biodegradable product.

G&G Bio-Bullets 0.25g
It's 0.25g. I generally use 0.25g BBs when playing airsoft.

Summary

We managed to overcome the initial challenges.

In addition, we were able to address another issue we discovered during the customization process—a problem with the slide not returning properly—by polishing the breech.

Regarding performance improvements through customization, this product is already highly refined, so the initial velocity and operation didn't change much. However, I was able to fix the incorrect assembly of the hammer unit and the slide return problem, so I'm personally very satisfied.

Also, regarding the hop-up, which I was concerned about, it can now be used from a hop-up adjustment setting of 0, so I think it will be able to handle even heavier BBs better.

Regarding the hop-up packing, the latest models use a knob-shaped type called BN hop, similar to those used by Tokyo Marui, which seems to eliminate issues with BBs falling out and the finicky nature of adjustments. However, I personally prefer the long-range type, so I'm happy that I can now utilize it, achieving my goal.

Finally, I wanted to check the room temperature to the usual 20℃ or higher for the final function check, but unfortunately, a severe cold snap caused it to drop to 6℃. It's a shame, but there's nothing I can do about it.

Thank you for your time.

Baton BM45 CO2 GBB
You can choose the color at the link provided. Black, black grip, and FDE (the model featured in this blog) are available.

BM45 Spare Magazine (Type-N, gasket, improved lip)
This is the latest magazine from 2022. Please note that the TYPE-N is an improved model with a modified lip and gasket, so be careful not to make a mistake when purchasing.

・1911 CO2 Magazine (Type-NL, gasket, lip, improved version with increased ammunition capacity)*Note: When attached to the 1911 or BM45, the CO2 cylinder will be visible from the outside.
Before I knew it, a version had appeared that had switched from single-column to double-column ammunition, increasing the magazine capacity from 15 rounds to 27. It seems the BN-SILENT HOWK is the main ammunition type, and with BM45 and 1911 versions, the CO2 cartridge is visible from the outside. It's a tough choice between ammunition quality and appearance (it's about 1000 yen more expensive than the one above).

・Baton (PUFF DINO) CO2 12g cartridge
These are genuine gas canisters. The manufacturer is Puff Dino, but Baton is the authorized distributor and treats them as genuine. It seems that only these canisters are eligible for the 3-month warranty. You can choose between packs of 6 or 50.

Marushin CO2 12g cartridge
I think Marushin offers the best balance of price and quality. You can choose between a set of 5 or 30. However, you will no longer be eligible for Baton's 3-month warranty.