G&P XM177E1 AEG High Cycle Customization Completed

This time, we'll continue customizing the G&P XM177E1 AEG, just like last time.

To recap from last time, after converting the gearbox's electrical system to FETs, the increased signal wires and thicker power wires got in the way, preventing the magazine from being inserted and the wiring from passing through the upper receiver. So, we'll address these issues.

Gearbox customization

First, I decided to abandon the idea of ​​using FETs and stick with standard front wiring. I'll rely on the SBDs to handle the switch burnout issue.

The SBD simply attaches to the motor terminals.

If you are interested in SBD, please refer to this.

Next, we will address the inconsistencies in initial velocity that we noticed during the operational test.

My prediction is that since I'm using Airsoft97's M100 spring with three teeth cut from the sector gear, the target muzzle velocity with 0.2g BBs will be around 92-94 m/s.

The forecast was for a minimum of 90 m/s, but it was 84 m/s, so there was a variation of about ±3 m/s. I will consider the cause (0.2g).

We suspected the cause was an excessive air supply to the barrel, so we focused on the acceleration cylinder.

I'm using the genuine part, and I'll compare it to the Laylax acceleration cylinder Type D (barrel length 251mm-300mm).

This is hard to understand, so I took a look inside.

The effective air compression area of ​​the genuine cylinder is considerably longer than that of the Lilux cylinder, so we suspect the cause is excessive air supply and will replace the parts.

Next, I'll remake the wiring using Eagle Model's 1.25 sq silicone silver wire, which is the standard front wiring type, and then install the Lilux Cylinder Type D.

All that's left is to close the gearbox and you're done.

Next, we'll install the gearbox into the receiver. The process is the reverse of the disassembly steps described in the previous article.

In many front-wired models, the battery connector cannot pass through the gap in the receiver, so the wiring is designed to be detachable using crimp connectors or similar.

To avoid problems such as connectors coming loose and rendering the system inoperable, I intentionally made the wiring longer so that the gearbox could be removed even with the battery connector still attached.

When removing the gearbox, I carefully pull the wiring to allow the gearbox components to move freely.

If you pull the connector all the way to the base of the barrel, the wiring will be long enough to allow other parts to move freely, making it possible to perform most tasks.

By the way, it's the usual T-type connector.

All that's left is to install the fuse and we're done.

Hop chamber customization

The hop chamber looks like it's well-made, so I'll use it as is.

However, the hop-up packing, push-in mechanism, and barrel will be changed.

First, let's look at how to disassemble the chamber, which I will explain with photos.

After that, you can disassemble it by carefully removing the barrel.

Incidentally, the lever that pushes the hop packing does not require disassembly; you can simply lift it up and push it in to replace it.

The parts I'll be using here are Miyagawa Rubber's Long-Hook Middle, 60 Hardness Nitrile Rubber (with hop-up rubber), and a Laylax BC Bright 260mm inner barrel with a 6.05mm inner diameter.

As usual, I'll modify the hop-up window on the inner barrel.

For details on processing the hop window, please refer to this page.

Next, I'll carefully assemble Miyagawa's packing into the barrel, applying Tokyo Marui high-viscosity grease.

Upon checking the amount of hop-up protrusion in the completed chamber, it is clearly insufficient, so we will modify it to slightly increase the amount of hop-up push-in.

Glue two 0.2mm thick plastic sheets to the hop-up rubber used by Mr. Miyagawa.

The amount of hop-up protrusion when this is incorporated will be as follows:

Minimum hop adjustment amount

Hop adjustment amount MAX

It's pretty good overall. Maybe even with the hop setting at 0, 0.2g might be too much hop, but you can just use 0.25g, so it's fine. The hops are coming down straight, which is good.

However, it seems that G&P's chambers, regardless of whether they are drum-type or not, don't have a very wide range of hop-up adjustment, so you'll probably have to adjust it by using different BBs.

Incorporating this completes the process.

Next, we will finally check the actual firing performance.

Live-fire performance verification

Now that it's finished, we'll proceed with testing its shooting performance as usual.

The conditions are that the battery is an ET-1 Redline LiPo battery, 7.4V 1200mAh, and charging is done in storage mode at 7.6V.

I'm using G&G bio BBs, 0.2g, with a slight hop-up applied.

It feels a bit lower than expected, but it's good. It can be used in indoor fields where 0.2g BBs are common and the initial velocity is under 90m/s, so it seems like it will be useful in a variety of situations.

The initial velocity fluctuation was within approximately ±0.5 m/s, so we can expect good accuracy.

Next is the cycle.

The battery fires 23.8 rounds per second at storage voltage, so when fully charged it will probably fire 25-26 rounds per second, which is exactly what I was aiming for.

If you're interested, please also check out my review of the chronograph.

Next is a video showing the actual operation. Please be aware of the sound as it is a video.

G&P XM177E1 Semi-High Cycle Custom

G&P XM177E1 Full Auto High Cycle Custom

It turned out great.

The noise level is also considerably quieter compared to when it was straight out of the box, and the mechanical noise has almost completely disappeared; the only sound you can hear is the clicking of the anti-reverse latch.

Incidentally, the reason the initial velocity is lower than the target value is probably because the inner barrel is relatively short at 260mm, resulting in a large air supply. With a similar configuration but a barrel length of 275mm, the velocity is often around 92-95m/s with 0.2g BBs.

I won't know about the ball flight until I get to the range, so I'll check it later.

The packing from Mr. Miyagawa, a reliable brand, is producing a decent initial velocity, so it looks promising.

This completes the initial stage.

Completed state

Although it's in its completed state, the main focus is on internal customization, so the exterior hasn't changed, but I'm posting photos for my own satisfaction.

Reverse

Short magazines really suit the XM177E1.

The magazine is a Tokyo Marui 190-round short magazine, and it feeds ammunition reliably.

Tokyo Marui Standard M4 Short Magazine
It's convenient because it can be used with most standard M16 and M4 electric airsoft guns. Its compact size makes it especially handy when playing in a sniper style.

The iron sights are perfectly adequate, but I added a red dot sight to enhance its combat capabilities.

Reverse

Ideally, if I had a mount that could be attached without a rail, I could use the standard AIMPOINT M2 type and make it look like the Delta Force in Black Hawk Down, but I didn't have one, so I'll have to make do with this.

- No-brand M4 carrying handle rail
It can generally be attached to M4-style carrying handles. However, it seems that CYMA's handles have unique dimensions and could not be attached.

G&P's electric airsoft guns are highly recommended because, as expected, they look really cool, but unfortunately, they are not readily available on the market, which is a real shame. It's also a pity because they're not too expensive and offer good value for money.

The XM177E1 and XM177E2, which are particularly popular, are rarely seen, so I'll introduce some electric airsoft guns from G&P (with the same gearbox structure, VER2).

G&P AR 9mm SMG AEG
A US military SMG from the Vietnam War era. The M16 receiver combined with the oddly sized 9mm magazine looks really cool.

G&P M16 Vietnam Version
This was a mainstay rifle from the same period as the XM177 series.

G&P M4A1 AEG Marine Corps Model
定番です。

Final specifications and summary

So, as usual, here are the final specifications and summary.

In terms of specifications, it uses a G&P gearbox ver.2 with a rate of fire of 25 rounds per second and a muzzle velocity of 90 m/s with 0.2g BBs.

The final parts used were as follows:

That's everything.

Looking back, it seems like there are fewer original parts inside the gearbox, but I'll try not to worry about it.

Summarize.

To be honest, this was a very difficult model to customize.

The gearbox itself is a standard Ver.2 so it was quick to assemble, but the exterior parts were quite unique and difficult to put together.

For example, the lower receiver of the gearbox was secured using bolts that normally fasten the stock pipe, and the mechanism for the dummy bolts was unique and quite challenging to implement.

Also, I struggled because it was a front-mounted wiring job, which I personally don't have much experience with.

In particular, there are narrow holes at the base of the upper receiver and outer barrel, and the wiring must be passed through them, making assembly quite tricky.

However, it's not all bad; there are many advantages, such as its good appearance, the fact that the gearbox is very firmly fixed to the lower receiver resulting in stable muzzle velocity, and the surprisingly good quality of the hop-up chamber.

My personal impression of G&P products is that while they have good potential, you need to be quite determined and committed to customizing them, otherwise it will never be finished.

If you're not too concerned about the appearance, CYMA's might be easier to customize (I'll try buying one next time).

In any case, I was relieved that my wife's airsoft project, which started with the ICS M4, was finally complete.

To be honest, I'm pretty exhausted. I don't feel like touching front wiring or specialized gearboxes for a while.

Thank you for bearing with me through this lengthy explanation.