VFC AEG Mk18 mod1 High Cycle Custom: Chamber Modification

Continuation from the last time will be important.

In the previous test, I discovered an air leak in the hop chamber, so I decided to go ahead and get an aftermarket chamber.

The hop-up chamber I chose is the Maxx MODEL CNC Aluminum HOP-UP Chamber ME-PRO, for nozzle lengths of 21-21.5mm.

The name is long.

The reasons I chose this model were its airtight design, the presence of an O-ring at the fitting point between the gearbox and the chamber, and the presence of three springs that press the chamber in place.

It's a bit pricey, but I was a little frustrated after the previous trouble, so I bought it.

Checking the MAXX HOP chamber

First, here's how it arrived.

It's surprisingly small.

Next is the instruction manual.

Overall view

There are a lot of parts.

Now let's look at the parts.

This is the chamber. The two powerful springs at the front of the photo and the O-ring at the nozzle insertion port ensure a strong airtight seal.

Let's start by looking at the nozzle side.

It's a very flashy design.

Apparently, it has a mechanism to prevent BBs from falling out when you remove the magazine. It's a small but nice feature because the BBs don't fall out when you're shooting indoors.

Next, let's look at the lever that pushes in the hop rubber.

Because it's a seesaw type, the part that presses the packing and the arm are separate.

A standard type hop-up arm is also included.

Two different lengths of levers for long-range hop-ups are included, as well as a lever for a standard cylindrical hop-up rubber.

Furthermore, the linkage mechanism is designed to prevent the hop-up rubber from tilting when the hop-up is pressed down.

This time, I decided to use the shorter version for long-range attachment. Incidentally, the longer version for long-range attachment requires modifying the barrel's jopp window to make it considerably longer before it can be assembled.

Also, since it's a high-cycle gun, I thought that if the hop-up protrusion wasn't rigid enough, the BBs would scatter during full-auto fire, so I procured a long-grip medium hop-up rubber with a hardness of 60 from Miyagawa Rubber. (Last time I used the slim hardness of 60.)

The thickness of the protrusions differs.

The rest is just assembly as usual.

The hop protrusions are coming down quite nicely.

As always, getting the hops to the center was a real challenge.

Thanks to all the hard work, I think the hop rate has decreased quite nicely.

This completes the initial stage.

Actual firing performance

Now for the nerve-wracking measurement.

The measurement conditions were the usual ET-1 REDLINE 1300mAh 7.4V with a storage voltage of 7.8V, and the BBs used were Tokyo Marui Bio 0.2g. The hop-up was set to 0 on the scale.

Oh, that looks great!

Next, I measured several shots with a semi-automatic mode, and they were almost all around 95 m/s, within ±0.4.

Even if you apply more hop-up, the initial velocity doesn't drop much.

The more hop-up you apply, the smaller the fluctuation in initial velocity becomes.

Looking at the motor specifications, it runs at 31000 rpm at 4V and 46000 rpm at 11.1V, so a simple calculation suggests it would fire 39 rounds per second. (Although the actual result is probably not that simple.)

However, it's not designed to last that long.

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

Semi-automatic rapid fire (video) I'm an old guy so I can't pull the trigger fast enough

VFC MK18 mod.1 AEG Semi-High Cycle

Fully automatic (video)

VFC MK18 mod.1 AEG Full High Cycle

The initial velocity was a little higher than planned, but I think it will settle down to around 92-3 once the spring sags.

After much struggle, it's finally finished.

I was able to achieve a high-cycle setup with a spring that wasn't too strong, which is my preference.

Since the load wasn't very high, I think we were able to ensure a relatively good level of durability.

Also, purely by chance, the semi-auto firing stopped at the pre-cocking position. (It can be deactivated with full auto.)

The chamber window is made of transparent acrylic, so you can see the movement of the nozzle, making it easy to determine the piston's stopping position.

The finished exterior

Then, I added some accessories I had at home, and it looked like this.

The girl

Getting carried away, I went to the other side

I can't wait to put it into practice.

VFC MK18 mod.1 AEG Full Metal Tan Color (Officially Licensed Version, JP Version)
This is the main article. It's also available in black in addition to tan.

The VFC Mk18 mod.1 has a 10.3-inch barrel, but the RIS2's 14.5-inch barrel is also cool and highly recommended.

VFC VR16 RISⅡ Daniel Defense
The engraving is different, and the internal components have been slightly upgraded. The link is for the 14.5-inch tan color.

Deployment in combat and ballistic testing

At the time of writing this custom review, I couldn't go out and play due to the COVID-19 restrictions, so I couldn't check the trajectory. However, I finally went to Yanex's regular game at their forest-style outdoor field in Noda City, Chiba Prefecture, so I was able to get a feel for it in actual play and check the trajectory.

First, regarding the initial velocity, I measured it at home with a 0.2g BB and got around 95m/s, but for some reason, when I measured it in the field, it was around 93m/s.

It turned out just right.

Incidentally, when I measured the cycle rate with a fully charged 1200mAh 30c LiPo battery, it reached 30 rounds per second.

First, I adjusted the hop-up using 0.2g BBs at the range.

I usually use 0.25g, but I had a lot of 0.2g left over, so I used it to use it up.

The hop-up adjustment worked well at level 3 out of 10, so it should be able to handle heavier BBs as well. I feel like it could handle up to 0.3g.

The trajectory was straight for about 40 meters, then it rose upwards and fell about 50 meters away.

I'm mostly satisfied because it turned out pretty much as I expected.

I zeroed the red dot sight at 40m, and it felt like I could aim quite accurately and the bullets flew fairly well up to around 40m.

It's not like the range is shorter just because it's a high-cycle weapon.

As expected, since the custom modifications didn't involve extreme barrel or sector cuts, there were no problems as the inner barrel and cylinder air volume were sufficiently maintained.

Here's a summary of the trajectory differences between various manufacturers' hop-up packings and buckings →I tried making my own G-HOP, part 2: Trajectory testing and practical application (comparison of hop-up packings: Miyagawa Rubber, Maple Leaf, G-HOP modified)

I think it would go even further if I used heavier bullets, so I'll try that next time.

The initial velocity is also good, and the hop-up adjustment range is sufficient, so I'll be using 0.25g and 0.28g BBs (most fields only support up to 0.25g).

Based on my experience using it, I was able to get some pretty good hits.

It also works with burst fire, and if there's bush, you can fire in full auto and it will penetrate, so you can take down your opponent as soon as you spot them.

However, it was so easy to use that I felt a bit hesitant to use it, so I only used it for two or three games.

Therefore, we were unable to use a sufficient number of rounds to judge fuel efficiency.

Nevertheless, brushless motors are inherently fuel-efficient, and their control boards include automatic stop functions for abnormal situations (mainly overload) and low battery voltage, so fuel efficiency shouldn't be a problem.

In terms of handling, the 10.5-inch barrel and weight of around 2.5kg meant it was hardly tiring to handle and very easy to maneuver.

Next, regarding its drawbacks in actual combat, the high-cycle design results in a loud and noticeable piston impact noise.

I'll just accept that this is unavoidable.

Furthermore, due to the high rate of fire, some magazines couldn't keep up with the feeding.

In particular, the 500-round high-capacity spring-wound high-capacity magazine (S&T) wouldn't feed the bullets.

In actual use, it worked exactly as intended, and I'm very happy with the result.

I'll continue playing with these settings for a while.

For measuring initial velocity and checking trajectory, white is recommended for better visibility (black is difficult to see). I personally prefer G&G, so I recommend them (they're not as accurate as Tokyo Marui, but they offer good value for money).

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.

Trouble occurred afterwards.

A problem occurred during the subsequent airsoft game.

When customizing my MK18 or using it in airsoft games, I always used MAGPUL PTS PMAGs (spring-fed, 120-round?).

This is an original part for the MAGPUL MASADA electric airsoft gun, and it was popular and widely available on the market at the time (it's probably out of production now).

It seems that the MK18 was able to fire in full auto mode this time thanks to the excellent feeding performance of this magazine.

With other magazines (both high-capacity spring-wound and spring-loaded), I couldn't feed rounds in full-auto mode. Semi-auto mode worked fine, though...

Since the main focus is on cicadas, it's fine as is, but I'll make some corrections because it's annoying when it doesn't work properly.

So, next time we'll cover identifying the cause and countermeasures, checking the actual firing performance and the recipe, and a summary—it's packed with information. Please join us if you're interested.