Evolution 2: A&K M4CQB

On February 8, 2008, in Evolution, by Gerry

The M4 Close Quarters Battle Receiver is an American Special Forces staple, an icon of modern warfare as waged by those secret squirrel snake eating operators. Does its awesomeness survive translation through Chinese xerox engineering in the form of the A&K M4CQB airsoft AEG? Wannabe Airsoft Navy SEALs (and Delta Farce too!), this video is for you!

Technical Notes:


The spring is slightly softer than the M120. I’m guessing the strength is around SP110 but the length is longer than the M120. Longer than an SP120, even.

The cylinder is closed type, which might explain why the bb spread is like an MP5. The cylinder’s inner lining is larger in diameter compared to other cylinders and the cylinder head is a bit wider too. If you mate the A&K cylinder head with a cylinder from say a Generic M or an R6, you’ll get a very good seal even without teflon. On the stock A&K cylinder, however, you’re going to need to fix the seal with teflon.

The air nozzle hugs the tip of the cylinder head tightly and provides a pretty good seal. No need to replace with an airseal nozzle.

Gears are branded as A&K and look like the standard fare steel type like XYT. There’s not much grease on them nor on the piston. Piston head is already ported and the o-ring that comes with it is okay.

The gearbox itself is not a reinforced type and looks to be close enough to the Marui design.


The gun is front heavy thanks to the all metal construction of the front assembly and the top receiver. The crane stock is plastic, though the tube is metal. Lower receiver is plastic, as well. The LMT sight is fully adjustable, although sighting through it is not as good as using a sight from a Marui or even a Generic M.

The top rail of the RIS on the CQBR sits higher than the upper receiver top rail which makes old-school sebone rails unusable. The new type of CA sebone rail that has bolts that go vertical will fit quite well as there are already threads waiting for the bolts at the exact positions. The top rail of the CQBR is positioned the other way around, however, which is a minus on aesthetics. They do have nice markings, though.

Bottom rail has a silver metal plate that prevents looking inside the RIS. The side rails come with rail covers already.

The front assembly is a one piece design and has a gas tube to increase rigidity. The flash hider is fixed with a hex screw and uses the standard 14mm CCW thread. The triangular sight is fixed using two pins and a hex screw. The positioning of the hex screw is bad, though, as you have the front swing swivel blocking the way. Granted that you can remove the front sling swivel before unscrewing the hex, it’s harder to return the sling swivel afterwards. Also, since they used a small hex screw, you WILL have trouble with it getting stuck and have no other means to remove it as these are notorious in stripping small hex tools.

No complaints on the top receiver. The takedown is still the standard Marui design and does not give you too many problems like the Metal M. Hopup assembly is still the standard two-piece design.

Lower receiver does not have A&K markings but it does have a square stamp on it. You can put your own sticker or carve something on it but I would have rather gotten a clean lower receiver as opposed to one having a square on it. Everything that should metal is metal. No other complaints here.

One thing to note, though. It seems that Marui receivers are not 100% fit with the A&K receivers so make sure that if you’re going to get a Zeke lower or something like that to have a full metal gun, you better check if it mates that well. It does line up and the pins do go through but you will see a small gap. I’ve tested A&K receivers with Generic M receivers and they are a perfect match. Perfect enough to suspect that they use the same metal cast mold.

The crane stock is a copy of the CA design although the butt plate is not removable. The manual gives you instructions on how to install the crane stock batteries. There are many inconveniences, though. It’s hard to put the batteries into the crane stock and you can’t put the battery covers without batteries in the crane stock as they will not sit well and will prevent you from placing the stock through the rear tube. The middle battery cell of the stock 8.4V sub-c battery pack will also make it almost impossible to adjust the rear stock fully forward as it will get in the way. There is a way to make the stock go fully forward with the battery inside it and it’s by making sure that the middle cell goes INTO the tube. With a 9.6v battery pack, this won’t be as much of a problem, I think.

All in all?

The CQBR is a very heavy rifle and if you think that the JG Spetsnaz is heavy then don’t get this gun. It’s very much front heavy. With the stock battery, the ROF is slower than other stock guns. This may be attributed to the long and stiff spring they used. Also, the internals need more lubrication. You will also notice that it doesn’t shoot that accurately thanks to the mismatched cylinder. I suggest getting a type 2 cylinder from a well r6 or r5.

If you’ve salivated over the CA CQB like I have, you will appreciate this gun. If you just want a CQB weapon I suggest you get an M733 instead, unless you don’t mind the weight.

FPS results, by the way are 310 fps on 0.25g bb’s. Consistent fps with deviations of just 3-5 fps. 310 fps on 0.25g translates to 347fps on 0.2g btw. And that’s with air leaks in the cylinder head.

What do you think of the A&K M4CQB? We’d like to hear your opinions in the comments!


Hello again and welcome to another edition of PinoyAirsoft.

Tonight we cover A&K’s M4CQB.

The Armalite design has been around a long time, its one of the more common types you will see in the field. So how does this variant compare to its siblings?

The first thing you will notice about this design is its shorter than your standard M4 Carbine. This makes it ideal for close combat situations. It features what in the real world would be the Close Quarters Battle Receiver or CQBR. This is somewhat the successor of the earlier Colt Commando variant of the M16. In the airsoft arena, its good dressing to complete a US Navy look. Nothing else screams VBSS or SEAL than the Mk 18 Mod 0.

Back to our airsoft replica, you get this handy design in a nice metal filled package.

In the box you’ll find the a custom three part battery, some BBs, A high cap, the airsoft carbine, there’s RIS covers and a front grip in there too. and of course a manual.

At first glance you’ll notice some nice detail. The cutoff SEALs sight is authentic. There are T markings on the RIS. The front grip helps lift that heavy metal front end. You get a snub length barrel with triangle sights.

But what would an ACM be without its flaws.

The large screw on the front rails is supposed to be near the front sights not the delta ring. There’s a metal plate visible from the lower rails. Trademarks are absent on the receiver. The front rails sit higher than the upper receiver. Our unit had some minor dings and scratches. And those are just the cosmetic faults.

The trigger mechanism has a tendency to get stuck in Semi or Safe mode. But when it does fire it can do 310fps. Not bad, though not great. The BB spread is the same as you’ll find on most MP5 airsoft guns, about 49mm deviation. It’s definitely not for sniping.

And one last thing, you’ll have no hope replacing your battery in the middle of a firefight (time lapse of battery replacement). The crane stock is a copy of the Classic Army design though the butt plate isn’t removable. The stock are difficult to put in thanks to the middle battery. And you can’t install the covers without inserting the batteries first. Best to bring a side arm in case you accidentally pull the stock out.

So why are we ragging on this gun when we had such praises for it at the start? We’re not. You would have to pay (2x?) to modify the equivalent Generic M to these specifications. And nothing comes close in shear amount of metal parts. It may be POT metal but it’s solid. It’s an ideal project gun.

Like the S-System before it, the gearbox is based on the Marui type 2. Inside you’ll find steel XYT gears and an SP110 equivalent spring. It uses a closed type cylinder which might explain the mp5ish BB spread. Except for a slightly larger inner lining on the cylinder and odd size bushings, the internals are quite standard. The gearbox isn’t reinforced but the piston is already port and air nozzle already hugs the tip of the cylinder seal. No need for a special airseal nozzle. The only obvious additions we could think of would be better lubrication and a Generic M or R6 cylinder to give a better seal.

On the externals the front assembly is a one piece design and a gas tube to increase rigidity. The blank space where trademarks should be doesn’t have A&K stamped on it. Since the lower receiver is plastic you’re free to etch your own trades. One thing to watch out for though, the lower receiver isn’t a 100% fit Marui. You’ll need something like a Zeke lower to have a full metal gun. The lower from a Generic M also fits nicely.

Overall this gun is very promising for upgrades. Knowing its faults, its still a good base for a upgrader who likes close in scenarios.

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