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Maruyama MP9 First Impressions
🕑 Added 2025-10-09 20:32:29 +0000 UTCThis one's been on our radar for quite a while as something a lot of airsofters seem to be interested in. We got our hands on one and have started our usual battery of tests.
Here are our initial impressions, in no particular order:
The externals of the gun are mostly plastic, but it appears to be a decent nylon as is typical for VFC/Maruyama guns. The muzzle is steel, while the bolt carrier is aluminum.
It's a very light gun. With just a Romeo 5 and loaded magazine- so the above configuration minus suppressor and light- it weighs just 3.3lbs / 1.5kg. It balances well and controls are well-designed and well-located. The stock is minimalist and has a bit of flex if pressure is applied, but does the job and provides a good cheek weld.
Magazines are exceptionally light at around 240g empty. They hold up to about 20g of gas without siphoning, and 45 BBs or so. They are very difficult to load out of the box but do break in with use.
While the bolt appears to have very little travel due to its position relative to the ejection port when fully to the rear, it's partially an illusion of the telescoping bolt design. The total travel is about 4.2cm, which is more than an AAP-01 (~3.7cm) but less than most conventional pistols (4-5cm).
It doesn't have a lot of recoil- it's fairly comparable to a pistol in a carbine chassis, like a Flux Raider or Maruyama or Aegis FMG. The cyclic rate, however, is extremely high, which in combination with some aspect of the fire control and nozzle design (we're still exploring this) causes noticeable siphoning and rapid cooldown in full auto.
As a result, while gas efficiency is quite good on semi at about 12 shots per gram- translating to about 240 shots on a complete fill- in full auto it struggles to clear even a single magazine. Under-filling is definitely required for extensive full auto use but siphoning occurs even with very little gas.
With the mag chilled to 38F / 3C, the gun will not cycle far enough to reliably pick up a BB.
Hop performance out of the box is mediocre, with overchambering readily visible (resulting in inconsistent amounts of hop) with .32g BBs. It uses a standard VFC blue bucking paired with an AEG-style solid cylindrical nub. Replacing both of these with 4UAD bucking and nub yielded immediate and tremendous improvement. Luckily, the hop is very easy to access, involving just one pin and one screw.
Hop adjustment can be performed by either field stripping the gun (clumsy, annoying) or by inserting the required 1.5mm hex key through a hole in the top rail. Note that in the above photo, the Romeo 5 is as far forwards as it can be without getting in the way of the hex key. Without its optic protector, one slot farther forwards might be doable.
The trigger pull is heavy and unpleasant, on the border of what we would consider comfortable to rapid fire. It has a long take-up and significant overtravel, both of which can probably be eliminated by shimming.
The fire control group and nozzle are heavily based on VFC G18C equivalents, and some parts appear to be interchangeable with that gun. So far, at least one user has reported failure of the hammer bearing spring, a known weak point on G18Cs. This should be fairly straightforward to solve using off the shelf parts.
And lastly, the gun is short-stroked by both a plastic puck and a rubber buffer. The gun was clearly designed around the inclusion of the puck, and its removal would also require substantial alteration to multiple operating parts. The rubber buffer, however, can be easily removed without adverse effect- except that it appears the increased travel and accompanying changes to recoil characteristics cause the bolt catch to frequently bounce up and catch the bolt. A stronger spring might alleviate this, but regardless, the impact to recoil and cyclic rate of removing the rubber buffer is not significant.
In summary, the performance and general behavior are consistent with those of a select-fire pistol. Players expecting rifle-like recoil characteristics will likely be disappointed, and full auto is only marginally usable. However, as a compact backup gun, sidearm, or CQB primary used in semi-auto, the good efficiency, good ergonomics, light weight, and high achievable accuracy make for a more capable alternative to a stocked handgun or equivalent. It may be possible to eliminate siphoning and improve cold weather performance by adjusting spring tensions, and there is certainly scope for increasing bolt mass, but more testing will need to be done.
Let us know if there's anything in particular you'd like us to explore.
Comments
JorgeLTE
Not disappointed by the Patreon content. It is a lot of hard work! Thanks so much.
Ross Radford
In this case, it looks like a combination of skinny mags (low surface area for liquid to vaporize) and high cyclic rate (pulling a lot of gas in a hurry). However, we have found some improvements in this regard that we'll be showing in the review.
Ben Fennell
What causes a gun to be so prone to siphoning in full auto? Is it inherent to skinny magazines like machine pistols always have or is it a design flaw that can be overcome?
Ross Radford
We're inclined to say that the more normal piston, hop, and nozzle designs, simpler takedown, and better mags are worth the price of admission alone, but we have a friend loaning us a Wii-Tech upgraded KWA for comparison that will be either directly in the review or in a follow-up.
Flotsam
Interesting. I guess the major qurstion is how it compares to the ancient KWA offering.
Ross Radford
We've had some experience with both the VFC and WE G36s and one of our members has been considering a MG36 build, so it's definitely on our radar.
Ross Radford
The selector is easier to use than the crossbolt, with a short throw from safe to semi and then another 135 degrees to auto. It is positioned very close to the bolt catch, which feels a little awkward/finicky, but isn't functionally an issue. It's also fully ambi since it's duplicated on the right side. In fact, the mag release can be actuated from both sides, so all controls are fully duplicated. As for the APC9, they're the exact same mags.
Claus Økær Holdt Hansen
How is the selector, compared to the "crossbolt" selector? And are the magazines compatible with the Maruyama APC9?
WolfMan720
Looking forward to seeing what the aftermarket might bring to this gun. I’m just happy to see more competition for MP9s. As far as exploring other stuff goes, would you guys be interested in diving into the G36 gbb platform? (Whether it be VFC or WE) I’d love to see what you guys think of it
