BATON BG-17 CO2 GBB (Glock 17 GEN.5) Frame Disassembly

Last time, we disassembled the slide of the Baton BG-17 CO2 GBB (Glock 17 GEN.5).

This time, we'll take a look at each part while disassembling the remaining frame.

Similar to the slides, there seem to be some minor issues at the time of writing (February 4, 2023), so I will proceed while checking each component from my perspective as a former engine designer.

We will proceed while also considering the direction of customization.

The product I'm disassembling this time has been used by me for test firing, approximately 300 rounds.

Overall view of the chassis

Before disassembling it, let's take a look at the overall structure of the chassis.

Let's take a look from a direction where the internal mechanisms are visible.

From a rough overview of the overall mechanism, I personally feel it's similar to the UMAREX/VFC Glock (Tokyo Marui's Glock 18C series).

Next, let's try attaching the magazine.

When I simply attached the magazine, the height of the magazine surface and the height of the hammer unit surface became the same.

Next, try attaching the magazine by lifting it up (check for any looseness in the magazine).

The entire magazine lifts upwards due to the play in the magazine. At this time, the surface of the magazine protrudes upwards relative to the surface of the hammer unit.

My personal opinion is that the design settings were simply considered with the magazine attached (there's no reason to deliberately shift the surface).

As of the time of writing (February 4, 2023), it appears that the difference in muzzle velocity is due to the play in this magazine. I believe that the play in the magazine catch is set too high, causing the magazine to protrude, resulting in a tight seal between the magazine's gas outlet and the slide's gas inlet, thus increasing the muzzle velocity (an irregular design condition).

Depending on the specific model, mechanical design involves calculating interference between objects in units of 10 microns (or even 1 micron when pushing the limits). Therefore, using the magazine in a protruding position (where it generates high muzzle velocity) is highly likely to cause interference with other parts such as the slide nozzle's tappet, potentially leading to damage (the magazine's gas route seal will be torn to shreds).

If you're concerned about the magazine's looseness, I recommend avoiding trying to fix it while the magazine is lifted up (the point where the muzzle velocity is being produced).

I think the play in this magazine is simply a mis-engineered dimension between the magazine's recess and the magazine catch's protrusion (a 2mm gap is unusual). I checked the magazine play in several gas blowback guns I own, and it was around 0.2-0.5mm.

Disassembling the frame

We'll start by disassembling the front part of the frame.

We'll start by removing the spring from the slide lock lever.

The trick here is to use a flathead screwdriver to press down on the square-shaped spring and shift its position towards the front of the photo.

Remove the spring that you shifted.

While most levers typically use coil springs, I personally think it's a good idea that this one uses a deformed spring.

With a regular coil spring, it's difficult to balance both sides of the slide lock lever, making it cumbersome to handle (it's hard to move the lever by holding both sides with your hands), but thanks to this modified spring, ease of use has been significantly improved.

Next, we'll remove the trigger spring.

When removing this spring, I often use tweezers (tweezers with fine tips).

Tamiya Curved Tweezers
It's very useful for installing small springs.

The trigger spring has been removed.

Next, remove the slide lock lever.

Since the spring that secures the lever has already been removed, you can remove it by sliding it sideways.

Next, remove the screws that secure the internal frame.

Next, remove the pin that secures the trigger.

Please note that this pin must be removed in a specific direction.

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.

This allows you to easily remove the internal frame from the front of the frame.

When you pull out the frame, the slide release lever and lever spring will come out, so be careful not to lose them.

The components are shown in the following photos.

Removal of the hammer unit

Remove the pin using the pin punch and handgun block mentioned above.

Please note that this pin also has a specific orientation.

Next, remove the screws that secure the hammer unit.

This allows you to remove the hammer unit, including the trigger.

These are all the parts that were removed.

The trigger plate is made of a moderately thick sheet metal, and I believe it's made of SP material (ordinary sheet metal), which is a common type of iron used for pressing.

Let's take a look at the triggers.

It features a trigger safety that utilizes the elasticity of the resin (a standard feature on Glocks). I'm concerned about the relatively high load of this resin spring.

Next, we'll investigate the cause of the poor trigger feel that I noticed during the product review.

From what I can see, the corner of the safety (yellow line in the photo) seems to be slightly interfering with the chassis. So, I think a good solution would be to chamfer the yellow corner where it's making contact.

However, if you chamfer too much, the safety feature will be compromised, so it's best to do it little by little (cutting the corners with a sharp cutter is also effective).

My impression so far is that while the adoption of MOS has resulted in considerable care being taken to ensure clearances between each part, it's puzzling that there are areas where the finishing is lacking, such as the looseness in the magazine and the corners of the trigger safety (perhaps because there are multiple designers?).

Hammer Unit

Let's take a look at the removed hammer unit.

This is a side view. The knocker return spring is easily lost, so this photo shows it in a state where it has been removed beforehand.

This is the back side.

Let's rotate it another 90 degrees clockwise and take another look.

Next, rotate it another 90 degrees clockwise to reach the contact surface with the magazine.

Looking at the hammer unit as a whole, I personally think it's quite similar to the UMAREX/VFC. This mechanism is based on Tokyo Marui's Glock 18C, and since maintenance and disassembly are easy, I think it's a good choice for those who are just starting out.

This is my personal method, but I'm going to disassemble the hammer unit.

First, remove and set aside the knocker return and knocker return spring, which are easily lost.

Remove the knocker spring by looking at the hammer unit from the back.

The tweezers I mentioned above come in handy here as well.

Next, remove the pin that secures the shear (use a pin punch and maintenance block).

Now you can remove the shear and spring.

Next, remove the pin shown in the following picture to take out the hammer.

Remove this pin carefully, as removing it all at once could cause parts to fly out.

Now all the parts of the hammer unit have been disassembled.

A quick look at the parts reveals no unusual components, and it appears similar to VFC's (I think it's based on the Tokyo Marui Glock 18C).

Each part, excluding the hammer, is made of diamond-cast aluminum, and the material is probably ADC3 T-6 or AC4D T-6, which are standard materials used in high-strength components in automobiles, so I think it should be strong enough.

If you're interested, please take a look at my explanation of the mechanism of the gas blowback hammer unit (understanding the mechanism will help you grasp the tricks to assembling, disassembling, and customizing).

hammer

Next, let's take a look at hammers that have been in the news for breaking easily.

We'll remove the parts and take a closer look.

When you look at it from the side

From a tactical perspective, the part that breaks off appears to have a decent thickness. However, it lacks the rounded corners designed to alleviate stress concentration at the base. Therefore, it doesn't look like it would break off easily. Moreover, since the material is likely iron-based, it should be quite sturdy.

On the other hand, the hammer spring certainly has a strong load. With Glock-type pistols, the spring shape is almost the same, and the number of turns is determined by the space between turns (2.5 turns), so the load is almost entirely determined by the wire diameter of the coil. In this product, the wire diameter is φ0.85, and even the VFC Glock 19X, which is said to have a stiff spring, uses φ0.8.

However, this alone doesn't seem like enough to tear off such a thick piece of metal from the hammer (and the material is probably iron).

The perspective I came up with here is regarding the manufacturing method of the hammer. Judging from the texture and appearance of this hammer, I believe it is not made of ordinary casting but rather manufactured using MIM, which is an advanced form of sintering.

It seems I've fallen into this MIM trap (I tried MIM for work around 2007 and got caught in the trap).

M(METAL), I(INJECTION), M(MOLD)

Here's a very brief overview of MIM.

As far as I understand, MIM stands for Metal Injection Mold, and it is an advanced manufacturing method that is an evolution of sintering (a method of molding by baking and solidifying powder).

To put it in rather rough terms:

The advantages are as follows:

These factors led to the idea that durable (high-strength) parts could be mass-produced cheaply, a concept that emerged around 2005.

Based on what we've seen so far, the hammer in this product has a complex shape that requires strength and can be produced in moderate quantities, making it a perfect fit for MIM (Metal Injection Molding). Furthermore, since MIM is experiencing a boom among medium-sized manufacturers in Southeast Asia, including China, in 2023, it's a manufacturing method that is likely to be chosen for this product.

Small, complexly shaped hammer

The ideal and reality (trap) of MIM

From here on, these are some of the pitfalls I encountered when I tried to implement MIM (Mechanical Injection Manufacturing) back in 2007-2008, when I was an engine designer.

First, we decided to try it with engine parts, as the manufacturer claimed that the molded product, which offered advantage 5, had a density of 98% and the strength was equivalent to that of the original material.

When we actually prototyped something using iron (at the super-large metal company H Metal)The material strength varied significantly, resulting in a strength of only about 7-8% compared to the original material (a gap between ideal and reality).

Further heat treatment should be possible.When I actually tried heat treatment, it didn't work well and ended up falling apart.

This surprised me, so I worked with the materials supplier to thoroughly investigate the cause.

To briefly list the causes:

Because of these factors, it is virtually impossible to maintain the same level of strength as the base material, which is one of the advantages of MIM, and the actual practical strength is only about 75% of the base material's strength (theoretically, if the process proceeds as ideally as possible, it should be 98%, but in reality, that's not the case).

Furthermore, as mentioned above, the variations in each process accumulate and lead to variations in strength. Because the variation is wide, the strength range was large, from 85% for good products to 75% for bad ones.

The investigation revealed that management is crucial, so even with significant investment in strict control of each process, the maximum strength we could achieve was 85-90% (ultimately, it was scrapped).

With all that in mind, returning to the hammer in this product, the designer took the MIM (Metal Injection Manufacturing) marketing claims at face value and set the material strength with a safety factor of around 1.0 to 1.2 (probably 1.2).

When actually mass-produced using MIM, the strength varies considerably, with hammers being mass-produced with roughly 7-8% of the required strength (it might be even lower in factories in the ASEAN region).

Assuming a safety factor of 1.2 for the product, I believe that even with a strength of around 7-8%, some parts will barely withstand the load, while others will not. If you're unlucky, you might end up with a part that doesn't hold, resulting in hammer breakage (the difference between a hammer that doesn't break and one that does).

I think the reason a fair number of parts fail to withstand the stress is because there's a significant variation in their strength.

When you actually look at the fracture surfaces of damaged items on social media, you see that they are not one-shot failures (breaking in a single instance) but rather typical low-cycle fatigue failures (fatigue failure occurring after a few cycles), which further supports my idea that it's simply due to insufficient strength.

Furthermore, the way it broke—a type of breakage not typically seen in iron-based materials—also supports the claim of reduced strength.

When using MIM, you should design with 7-8% of the strength of the base material, and you need to understand that variations in the process directly affect the strength (dimensional effects are the biggest in other processes), and that it is difficult to handle unless you understand the strictness of process control (experience is also important because nothing goes according to theory or catalogs).

Now that you understand the mechanism and causes of hammer breakage, let's consider how to actually deal with it (unfortunately, it depends on luck).

With molded parts like MIM, it's impossible to tell from the appearance which parts have lower strength, so I think the basic approach to reduce the load on the hammer is to lower the load on the hammer spring (a rough guideline for lowering the spring load is to reduce the wire diameter from the original φ0.85 to around φ0.6-0.65, slightly larger than the Marui genuine part, assuming a 2% reduction in material strength).

If you think you've gotten a lucky unit, the number of cycles it takes to break down in the low cycle cycle is approximately 1000, so if it hasn't broken down after more than 1000 uses, it's highly likely to be fine.

If I were the manufacturer, my first priority would be to select only the good products, but it's difficult to check for variations in strength using non-destructive testing, so selecting only the good products seems impossible.

We could also reduce the decrease in strength by strictly controlling each process, but that would be costly, wouldn't it?

Finally, the most straightforward approach would be to statistically measure the strength reduction due to MIM and then either modify the hammer's shape (which might be difficult due to space constraints) or reduce the load on the springs (depending on the impact on operability) (a combination of both is also an option).

It seems they've already prepared countermeasures for March and April 2023, so I'll wait and see how things develop.

By the way, I believe most of the internal components of LAYLAX's M17 hammer unit are also MIM (Metal Injection Molding).

I've gone on quite a bit about the hammer and MIM, but that completes the frame disassembly.

If you're interested, please take a look at the explanation of fatigue failure.

Disassembly of the magazine's gas route packing

Next, we'll take a look at the gas route packing of a magazine that's been trending on social media.

Disassembly is easy; simply remove the pin shown in the following picture.

It's not a recommended method and not a good one, but I removed it with a thin hex wrench (it's barely acceptable since there's no load on the pin?).

Let's take a look at the gas route packing.

Unfortunately, they were all completely ruined. All three of the ones I had were dead.

This can be fixed quickly, so I'll leave it at that.

HereIf you're using aftermarket gaskets, you should be very careful about checking the height (to avoid interference with the nozzle and tappet) and the muzzle velocity (a larger opening increases output). (Personally, I recommend rebuilding with the original parts.).

When I consider the cause of this peeling, I think it's simply a problem with the assembly method during mass production (these kinds of mistakes are fairly common at overseas locations because they are assembled quickly).

This slightly rough assembly reminds me of factories in the ASEAN region, and it brings back nostalgic memories.

Next, let's look at the magazine catch on the frame.

The magazine catch spring appears to be a leaf spring.

Leaf springs are sturdy and allow for a high spring constant, but their hysteresis is not very good as a spring characteristic. Therefore, the feel of the magazine catch is not bad, but it's not particularly good either.

That concludes the magazine.

Summary

My overall impression after disassembling the frame was that it was built using a mechanism that was true to the basics.

While the issue of the hammer breaking has been highlighted, I think the rest of the product is quite high-level (the mechanism seems more refined than the slide).

The movement of each part is also quite good.

However, the points that I found concerning are as follows:

- Trigger safety sticking

- The amount of play in the magazine height (I'd like it to be around 0.5mm)

- The gas route seal on the magazine is peeling off.

will be important.

All of these issues are easy to fix.

Overall, this product, including the slides, is quite high-level and a really great product, but I think it's a shame that it still has a few minor flaws (it could be even better).

Regarding the hammer breakage issue, I think the manufacturer will just have to do their best to resolve it. Personally, I think it's something that can happen when trying out MIM (Metal Injection) and is unavoidable, but as a consumer, it's a disappointing incident.

If you don't often disassemble your gun, this might be a good opportunity to try replacing the hammer spring. This product is recommended because it's a Glock with few parts and is easy to assemble and disassemble (there's a lot of know-how available online).

That concludes the frame disassembly section, although it has become quite long.

Next time, we'll decide on the direction of the customization based on the issues that arose during the disassembly process, and then proceed with the customization.

Baton BG-17 CO2 GBB (Glock 17 GEN.5 MOS)
If you buy it online, it's hard to tell before and after the hammer incident. With Amazon, you'll be taken directly to Baton, so you might want to contact them and confirm.

Baton BG-17 Spare Magazine
This magazine seemed like it would be quite durable.

・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.