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| November 12, 2019

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KWA KSC Glock RA-Tech CO2 Magazines

RA-Tech CO2 magazines for KWA/KSC Glock 17/19
Dave Miller

Review Overview

Sub-zero temperature performance

Not great.

A disappointing offering from RA-Tech. If you love KSC/KWA glocks and know what you are doing with gas mags then I would definitely recommend them, they do need work though.

Cost: £30 including delivery from RedWolf Airsoft (£10 tax on top of that)

FPS: 320 on 0.2g BBs

As you will have no doubt seen, WE have recently released CO2 mags for their glock platform. So what’s the big deal with CO2 mags?

CO2 holds a much higher vapour pressure in it’s liquid form than propane (IE green gas) does. At 20C – or a summer’s day – the vapour pressure of CO2 is 60 Bar and the vapour pressure of propane is 9 Bar. Now make it a winter’s day.

The pressure of CO2 is now 35 Bar, and the pressure of propane is 5 Bar, meaning that there is half as much pressure to operate the gun with. For propane, this results in lower FPS, a sluggish response and venting. For CO2, this results in a presssure that is still four times higher than that of propane on a hot day! In fact, to get CO2 down to 9 Bar your pistol would have to be used at -40C – meaning your gun would probably sieze before the pressure was too low.

What this translates to in airsoft is that CO2 is a power source that can be safely used in winter (as you’ll see later in the review, I test this mag at sub-zero temperatures), but does require some control. Letting unregulated CO2 into a bog standard mag and pulling the trigger would at best result in your gun not firing, and at worst result in it exploding in your hand (not good).

Some CO2 powered guns are more heavily regulated than others. For example, an 8″ dan wesson revolver kicks out north of 500fps on a good day, while these mags only kick out 320fps.

Science bit over! It’s time to see how the mag did.


I love my KSC G18c. It’s (in my opinion) a very good looking, very shootable pistol. I’ve bedecked it with RS accessories, had it in bits more times than I can remember and done a fair few games using just it and nothing else – did I mention I love it?

There is one problem in all of this. As it gets colder, it becomes less and less satisfying to use. Safe to say that for half of the year in the midlands it’s unusable, mainly due to being upgraded to the nines (hammer spring, recoil spring, metal body kit, the list goes on).

Enter RA-Tech. Producers of kit of varying quality, some stuff they make is truly phenomenal, where other stuff is merely average. Unfortunately these mags fall into the second category. Clocking in at 5-10 pounds more expensive than the standard mags depending on where you get them, I’d expect

these to flipping well work, and work first time.

The mag's packaging.

The mag’s packaging.


The key

The mag arrived in a simple cardboard box, simple as that. The mag appeared to be well made, and it is very very heavy. It is also supplied with a little steel key for screwing in the mags. The G19 mag has a longer baseplate, and a slightly different screw for tightening up the CO2 bulb. Other than that they are identical magazines.

I gleefully grabbed a CO2 bulb and installed it in the mag, no leaking noise whatsoever. Slapping the mag into the gun, I racked the slide and pulled the trigger.


After each shot the hissing got worse, till it was effectively venting.

Thinking it might be a one-off, I grabbed a second bulb, plugged it in and the whole thing dumped through the top of the mag in under a second.

An email to RedWolf explaining the situation was met by a response to the effect of “grease it up” – this I duly did, with no improvement. (In fact it got worse – the next bulb emptied in under a second after being installed in the mag). A week later a fresh magazine arrived on my doormat, completely free. (Massive thanks to RedWolf there!).

OLYMPUS DIGITAL CAMERAOLYMPUS DIGITAL CAMERAOLYMPUS DIGITAL CAMERAThis mag worked, which was brilliant. It meant I could actually test how it performed. The mag only takes 20 rounds, which is plenty, but it is a shame. The standard mags take 23 rounds, so it’s a shame that RA-Tech couldnt fit more rounds in this mag (which is in fact significantly longer than a stock KWA magazine).

The feed lips are quite different to KWA’s, much looser. The follower does not lock down, and it did seem quite tight at times (this was something that I had  seen as problem online). This did once cause a stovepipe jam (something I have NEVER had before on an airsoft gun), but that has only happened once in an estimated 2000 rounds put through the mags.



Hot weather shooting (25 Celsius) performance was unpredictable – sometimes light blowback occurred, sometimes full snappy blowback. One thing that was apparent was that the colder the bulb was, the harder the recoil – bodes well for the winter months!

Thinking that it might be a good move to see what these mags could do in the cold, I bombed it up, slapped it in the freezer along with the glock for 15 minutes and let it get nice and cold. 15 minutes later I let rip, firing off the whole bulb in about 90 seconds. I got 40 full power shots with the mag locking back on empty, and a total of 60 shots out of the mag before it vented. Don’t believe me? Have a video.

The mag chronos (at room temperature) at 320fps on .2g bbs, which is the same as my propane mags. Another +1 for the magazine.


The troublesome gas router & feed lips

With the RS mag catch installed in my glock the large red gas router that the mags come with is slowing the slide down before it fully returns to battery after releasing a locked back slide, meaning the slide has to be pressed forward before the gun will fire. If your standard mags feel a bit loose and mag shims just cause you problems, these red gas routers might improve things a bit. You can buy them from hong kong by themselves relatively cheaply – I’d recommend looking into it.

Non-feeding was an issue, with the followers often binding within the mag channel, preventing more BBs being fed to the gun – the mag needed to be ejected and the follower pulled down, a few rounds removed to get past the stick point and then the mag would start feeding again.

One final issue – the striker on the back of the release valves unscrews itself, which is a weak point. This can be solved with a quick drop of threadlocker though.

The teflon packing that needs to be sanded down is the white bit visible in this image.

The teflon packing that needs to be sanded down is the white bit visible in this image.

I have managed to fix the mag which did not work, and it was relatively simple. I bought a pack of 3mm inner diameter x 1mm cross section orings off ebay for about 3 pounds, and sanded down the piece of teflon packing shown here so that the oring could be pressed into the body of the valve on top of it. You need to sand off enough that about a third of the oring is protruding over the edge of the valve body, doing this means that when the gas is applied the oring is squashed by the valve head, bringing the striker on the back of the valve to the right height to be correctly struck.

The other problems with the mags can be easily fixed as well. Feeding problems by replacing the magazine spring with a KWA spring (the stock one being quite badly twisted in both mags), and the stovepipe can be avoided by replacing the mag jaws with KWA or Building Fire polymer ones. Once the KWA mag spring is installed you can replace the piece of pipe at the bottom of the mag with a KWA baseplate catch, which extends capacity to 24 rounds. Failure to battery can be solved by replacing the gas router with a (you guessed it) KWA one.

To conclude – these mags are a rough diamond. The concept is fantastic, the execution is disappointing. The overall mag is solid, but it is let down by the finer points, causing a host of technical problems in the gun. Once any leaking valves have been fixed, your springs have been replaced (I know you can get replacement PTW mag springs online, they might work if cropped a bit but that’s only a guess), and the other problems fixed as described above you really will have a fantastic magazine.

A final note – the pistol used for all this testing has been heavily modified. The pertinent parts include: Pro Arms 6.02mm inner barrel, ATP Cylinder, Firefly Rocket Valve, Guarder 150% hammer spring and Hurricane Recoil Spring. I have no idea how these perform in a plain jane KWA glock, though it wouldn’t be too dissimilar. Finally, thanks to my mate Col for letting me use his G19 mag for the review!