Heckler & Koch MP5K - Maruzen

I was having a bit of a clear out, when a Maruzen MP5K GBB appeared on the forum. As this was a gun I had wanted to try for some considerable time, I made an offer and pretty soon I was its owner.

Classic MP5 design.

There's a scene in Blackhawk Down, where Michael Durant's helicopter is surrounded and he grabs his MP5 (Oddly, the one in the film is not the MP5K aircrew actually used) and opens fire.

The scene from BHD - Courtesy Columbia-Tristar

That scene, alone, is probably why the MP5K interests me, but Maruzen's GBB version has a good reputation for realism, if not for being able to take stronger gas than 134a.

I am quite ambivalent about select fire airsoft GBBs, generally - They are fun, but sort of pointless and prone to more problems than their semi-auto alternatives - but I was keen to try the Maruzen MP5K.

In the Box

The box lid is the typical Maruzen plain beige card with a line drawing of the MP5K and their usual selection of 'English' exclamations, notably "NEW CONCEPTION FOR MORE BLOWBACK!".

No space for accessories in box.

The base is a big piece of polystyrene, which holds the MP5K very securely, with the 30 round mag fitted. There is no space to store either additional 30, or 50, round magazines in the base.

My gun came with a small bag of BBs and the usual collection of paperwork, plus a couple of glossy Maruzen marketing posters.

First Impressions

The Maruzen MP5K certainly looks good. The overall finish is a dark grey and great pains have been taken to replicate the welds on the real thing in the moulding of the Maruzen.

Weight, too, is impressive at well over a kilo with the short magazine and the gun is comfortable to hold either one handed or two, using the foregrip. Overall finish is, as I have come to expect of Maruzen, very good, with no significant seam marks and impressive looking trades.

Smart looking gun is quite big for a GBB pistol/SMG

Being left handed, the inclusion of a selector on both side is a big plus for me.

Quality of finish and detailing excellent.

Parts such as the cocking handle, rear plate (with a sling swivel), barrel end (including the foresight), rear sight, trigger and magazine release are all metal and look and feel solidly made.

Closer Look

Where to start... For some reason, I really struggled getting this review written, but...

The MP5K is a lovely looking gun, quite big for a GBB (aside from rifles and a few old 'classics', probably the biggest) and it feels solid and sturdy.

The plastic parts (on the real gun) are convincing and the 'metal' parts are quite different and, to the eye, appear metal like. Sadly, they do not have the 'cold to the touch' feel of the HW material used on some slides. To be really picky, it does have visible seams, which aren't as bad as, for example, a TM Beretta or even most of TM's AEGs, but are there and visible, something you would not expect of KSC or WA products.

Rear plate is metal and include sling swivel.

The rear plate is metal and features a sling swivel, which looks as though it is strong enough to take the weight of the gun quite happily. I suppose if you want to be picky, this and the front barrel/sight assembly should be a grey colour, more like the body, but I didn't find this particularly jarring, personally.

Cocking handle works as real thing, including 'safe' position.

Up front, the cocking handle is also metal and feels quite realistic as you pull it back and then let it return forward to cock the gun. It is possible to push it up into a cut-out whilst in the rear position, which acts as a safe position. The gun cannot fire with the cocking handle in this position.

Maruzen MP5K fires from an open breech, like the Micro UZI and M11.

There are a couple of quibbles, however, with the realism of the MP5K and one is that it is based on the Micro UZI/M11 mechanism, which fires from an open bolt. A real MP5K fires from a closed bolt, which would also help with preventing the ingress of dirt, etc on the airsoft version. The other quibble is that the MP5K, like those other two Maruzen full autos, does not lock back the bolt when the magazine is empty.

Front barrel, including sight, is solid metal

The sights are pretty good, with the actual rear sight drum (which rotates for adjustment) and front sight, along with the front end of the barrel, being metal, but you'd rarely use the sights, I suspect.

Rear sight nicely reproduced and usable. Disassembly pins, with retaining latches, visible.

Maruzen produced a MP5K with full auto, semi auto and safe trigger grouping (I am sure the MP5 groupies will know the correct terminology), failing to provide a burst setting, which I like on full auto GBBs, such as the Beretta M93R and H&K VP70M, which again can be blamed on the cheapness of the gas mechanism designed for the bargain basement Micro UZI, but is not critical as there are many variants of the MP5K trigger group-wise.

Attention to detail. Model and Serial numbers in correct place. Note, also, 'weld' marks

The markings on the gun look pretty accurate judging from the plethora of photos of MP5Ks on the Web. I particularly like, as noted earlier, the neat replication of weld marks and things like the Model and Serial number 'stamped' into flats on top of the receiver.

In terms of markings, the left side of the gun bears the 3 position trigger grouping markings and "Kal. 9mmx19" on the mag well

On the right side of the gun, the trigger group markings (and selector) are reproduced (and fully function - good for left handers) and the mag well bears the markings "MD409287"/Made In Japan/MARUZEN/JASG 6mm, a mixture of H&K and Maruzen trademarks, which don't look intrusive.

On the right side of the front hand grip is the number 548, which is repeated on the rear plate. The top of the gun is marked MP5K and 13548 on the top 'flats' on top of the receiver.

30 round mag (left) with 50 round extended version.

As standard, the gun comes with a 30 round magazine (a replica of the real steel 15 round magazine), but Maruzen also make a 50 round magazine, which is more useful for skirmishing and seems pretty good value when you consider how much magazine you get for the money, compared with some other GBB magazines.
The 50 round magazine is a replica of the full size MP5's 30 round magazine.

Shooting Impressions

As with most select fire GBBs, shooting the MP5K is where it really stands or falls. If it is good, you can overlook faults elsewhere, if not, the build quality and accuracy of replication are almost irrelevant.

Fortunately, the MP5K is wonderful, on the whole, in this respect. However, my initial feelings were otherwise.

Click on image for bigger version in separate window.

Carrying out my standard 5m/6 round, off hand test, the MP5K was remarkably good. Probably helped by the forward grip, I was able to put all 6 rounds on semi-auto into a 1.25 inch (3.3 CM) radius.

Click on image for bigger version in separate window.

Then I loaded another 10 BBs, switched it to F/A and pulled the trigger. The gun cycled, but it didn't fire anything - Oh dear, I thought.

Still, the magazine was emptied and I couldn't find the BBs in the barrel, so where were they going?

So, I stuck in another 15 BBs and fired again - Nope, target didn't budge, no signs of impacts, no tell tale white line of BBs to the target....

I decided to check the target, despite being convinced that I wasn't firing anything, and was stunned to find 25 or so holes all over the place!!!!!

This thing's Rate of Fire IS incredible and the BBs were zipping into my target without even ruffling the paper on the way through!

However, absolute FPS does not seem to be the MP5K's strength. Admittedly, it is very cold (Around Christmas), but even warming magazines before firing doesn't seem to raise the FPS significantly.

Over 10 shots, the Maruzen MP5K averaged just 240 fps (using Abbey Ultra gas) indoors (at 16C).

Shot      FPS
1 257.9
2 253.8
3 240.0
4 242.0
5 237.5
6 235.3
7 236.9
8 237.2
9 234.9
10 228.4

Warming the magazine first, the readings were in the mid-to-high 260s. Interestingly, using the 50 round magazine put another 10fps or so on top of these figures.

I will, for fairness, mention that many other reviews talk of 300 fps performance.

I have also, in cold conditions, experienced the oft-reported problem where the gun fails to cycle fully in semi auto. I have found this, usually, when the magazine is low on gas and is often resolved with a short burst on full auto. Basically, the problem manifests itself in firing once, but then requiring another pull on the cocking handle to fire again. This has the effect of chambering two BBs, so is far from ideal.

Update March 2005

As it was a warm day, our first of the year, really, I decided to test a few guns, amongst them the MP5K.

On Abbey Ultra Gas at 25C, 10 .2g BBs averaged 279fps over 10 shots, still shy of the 300fps mentioned elsewhere.

Take Down

Field stripping the Maruzen MP5K follows the real steel process.

These pins simply pull out.

With the magazine out, removing the pins above, allows the gun to be broken into lower receiver and upper reciver, with the rear plate coming off as well.

Broken down - Top part is the bolt.

The bolt can be withdrawn from the upper receiver at this point.


Overall, the Maruzen MP5K is a mixed bag. There are a few annoying features, not least its inability to lock back when empty, its relatively low power (perhaps it is unfair to judge in such cold weather, I will try and return to it when the warmer temperatures return in the spring) and the fact it fires from an open bolt, when the real thing fires from a closed one.

Fitted with 50 round mag.

However, the rate of fire is infectious and the overall build quality and shooting experience is very good.

Most people will not be bothered by detail inaccuracies to the real thing and will just enjoy the broad grin the Maruzen MP5K delivers whenever they fire it.

Weight : 1380g/1500g with 50 round magazine

Realism : ***
Quality : ****
Power : ***(In cold conditions)
Accuracy : ****

Real Steel link at World Guns

Real Steel link at HK Pro

Back to the Homepage