CYMA CM031 AK-74 Review
by aznriptide859
I would first like to thank nachosdesign2 for helping me decide on getting the gun and FTG_HK for providing me with the gun. Also thanks to BLKKROW for his video on YouTube of his FPS tests of his CM031.
History:
The original Avtomat Kalashnikova Model 47 is one of the world’s most used, and cheapest, assault rifles. It’s easily and cheaply built, doesn’t jam, and very reliable. The original AK-47 was designed to fire 7.62mm x 39mm rounds. The Russian government then redesigned a new version in 1974, named the AK-74, for use with the entire military. The first versions came with a full wood stock, handle, and handguard grips. This version, however, used 5.45mm x 39mm rounds. Later versions, namely the AK-74 issued starting from the 1990's, came with a new black plastic furniture, again for use with the entire Russian military.
Now, onto the review!
I. First ImpressionsI first found out about this gun via nachosdesign2 on ASR, and, after asking him a few questions and looking at his videos of the gun, decided to get it. I got it for $121 USD shipped from Hong Kong via FTG_HK, one of nacho’s team members. It took me a long time to collect the money, but once I did I paid and received the gun 5 days after I paid.
As I opened the package, I looked at the box, tore it open, and gazed at the beautiful gun. The package came with:
1. AK-74 AEG
2. 220v Asia-connector Mini Charger
3. 100bb packet
4. Front sight adjustment tool
5. OD Green 2-pt sling
6. 8.4v 1200mah Ni-MH mini battery
7. Hi-cap magazine
8. Manual
9. Unjamming rod
II. AppearanceUpon first examination the gun looks nothing like a toy. Up close the gun looks exactly like the real thing. Besides from the small screws connecting the stock to the receiver itself, and the absence of trademarks on the receiver, the gun looks almost alike to its real steel companion.
III. FeelAfter I first picked it up, it felt REALLY heavy. I weighed the gun at 6.9lbs with battery installed, which is pretty heavy for an AEG clone (this is the first I've ever bought). The gun is mainly front heavy, as most of the metal parts are in the front assembly of the gun. The battery only adds a bit of weight to the back, but it's not really noticeable. Only after putting in a large battery (yes, even though the connectors are mini, the compartment can easily hold a large battery...more on this later) does the weight balance out.
III. Build/External QualityWell, now onto the gun. None of the body parts are wobbly or anything and the whole gun is very, VERY well built.
Metal parts include: front sight, gas block, outer barrel, upper ribbed receiver cover, trigger guard, trigger, magazine release button, front sling hook, cocking lever, rear sight, and rear sling hook. The foregrip halves, handle, stock, and lower receiver are made of very durable plastic, unlike the CA’s model of fiberglass.
The metal parts were all painted matte black with a very good finish. The only bad part of (my) the gun was that there was a huge scratch mark on the right side of my foregrip. Probably a shipping or packing damage, but I’m fine with it. The gun was shipped with a small piece of red tape on the flash hider...I guess that’s the "blaze orange implement marker", thank you CYMA.
The flash hider is all-metal, even very heavy. It attaches onto the front sight via 14mm- threads, and can attach any other barrel extension with a 14mm- thread. The flash hider itself attaches onto the front sight via a small notch, where a button on the front sight holds the flash hider in place.
The front sight can also be adjusted via the small tool provided with the gun. There’s also a small screw on the bottom of the front sight (using a 2.5mm Allen wrench) to adjust the front sight left and right.
The rear sight is also all metal. It’s adjustable via the small push lever on the sight itself. The numbers represent the distance of the aiming; the higher the number you adjust the rear sight to, the further the distance you’re aiming down. The rear sight notch is a bit thin, and aiming down the sights is a bit difficult. A little Dremel work on widening the notch may solve the problem.
The stock is made of plastic, but is very durable and attached onto the rest of the gun very well. The rear sling hook is on the left side of it, and is always kinda loose (only part of gun that rattles around). The sling provided seems to be very sturdy, yet I haven’t combat-tested it yet. The stock is rear wired via a mini connector, yet the rear battery compartment seems definitely capable of holding both a 8.4v large battery or a custom 9.6v battery. The back stock cover is made of plastic.
The cocking lever is a very nice part of the gun. Pull back, release, and hear the satisfying *clink* of it hitting the receiver. Pulling it back reveals the hop up, which is similar to the CM028 hop up. Pulling the lever back towards the stock gives the BB more “hop up”. I’ll discuss the hopup assembly later.
IIIa. Disassembly (Front Section)I used a TM AK-47 Beita disassembly video (
http://www.mechbox.com/site/upgrades/index.html) which is very useful to take apart my CM031 today. It's very similar to TM in all aspects, but I found today that in the video apparently TM has a separate small piece for the magazine catch, but not CYMA...less pieces for me to worry about losing
. Here's some basic tips of taking the front assembly apart:
After following the video, you should have the gun split into 3 main parts: the receiver/stock, front assembly, and the cocking assembly:
Now, to remove the hopup assembly, you just need to remove the 2 screws attaching the hopup assembly to the front assembly. On a TM AK47 it can be just slid out, but I've had trouble with this process, so I've had to remove just a bit more...here's instructions.
First, following the manual, push in the small lever holding the front flash hider in place, and twist clockwise.
Next, there's a small hex screw right below the front sight, which holds it in place. Use a 2.5mm hex wrench to screw this off, and take off the front sight.
It might be hard to see, but behind the notch on the lower gas block is an even smaller hex screw, which requires a 1.5mm hex wrench to remove. Remove it, and slide the gas block off the outer barrel.
After this you can slide the upper half of the gas block off to remove the upper handguard half...
...then slide off the bottom half to remove the bottom handguard half. (Picture showing all of the front handguard assembly disassembled)
What's left of the front assembly after taking apart the assembly:
Now, to remove the hopup, I just wiggle the hopup assembly around, pull a bit, and it'll come out. However, to wiggle the hopup a bit, you probably need to remove the 2 screws attaching the 2 halves of the front assembly, as this will make it easier to take out the hopup assembly.
IIIb. CM031 Hop-Up AssemblyNow, onto hopup analysis:
The barrel is actually pretty long here. However, after purchasing a Systema 6.03mm Tightbore barrel (length 455mm), I found the CYMA barrel about 20mm shorter than the Systema one. However, the stock CYMA barrel is 6.08mm in diameter, which is pretty good.
Comparison of barrels, Systema on bottom:
Hop-up assembly installed:
The design of the hopup is very similar to TM, but internal functions are very different. The barrel has a small hook, just like TM-compatible barrels do to match the barrel up with the hopup assembly.
Now, for further inspection, I've been able to take apart almost the whole hop up. Here are all the main parts:
Now, after removing all main parts, I pushed out a smaller barrel inside, which contained the hop up rubber.
Upon inspection, the extended barrel (plastic) had the hop up rubber sleeve over it, which acted very similar to a normal TM barrel. Comparing it to the Systema barrel (on top), the rear assembly is almost exactly similar, and except the hop up rubber is a bit shorter. Here's the problem: The lever, as it's moved back and forth, pushes down another lever, which has an indentation inside of it. This pushes down onto the actual hop up rubber bucking inside the assembly. This is very similar to the TM model hop up, and has very much improved from the original rubber ring design from the CM028. However, in TM barrels there are small notches in the barrel where the hop up sleeve goes over it. In TM hopes the lever pushes down INTO the notch, so the BB is actually in the barrel as the hop up rubber stops it. But, in the CM031 hop up assembly, the BB stays OUTSIDE the barrel and on the hop up rubber sleeve; in context, the BB is adjusted hop up IN the rubber, and then fired, THEN it enters the barrel. As you can see 2 pictures above, the barrel has NO notches on it, so it's not TM-hop up compatible. So, if upgrading the hop up and barrel, new ones of BOTH need to be bought, approx. an extra $45-60 depending on where you look. All in all, the CM031 hop up is fine, but probably isn't as effective as a TM one. I don't see why CYMA didn't put a bit more effort and make the rear hop up PLASTIC assembly attached to the normal metal barrel.
IIIc. Gearbox AnalysisOk, here's the gearbox analysis
The gearbox itself:
The motor and motor cage:
Gearbox opened:
Spring guide. CYMA apparently made a bad spring guide for me, as the plastic still has bubbles in it:
Stock spring. The stock spring is longer and stiffer than the TM stock spring:
Gears set up inside the gearbox:
Anti-reversal latch:
Entire gear set. All the gears on the back state it's a CA gear set, improved from the original XYT gear set.
Gearbox shell. There's a lot of scratches on it (probably due to an improper shim job), and not a lot of grease (CYMA uses a clear type of grease):
Air nozzle. Again, made of clear plastic. The inside of mine was a bit dirty so I had to clean it:
Tappet plate. It says "AK SIG" on the bottom (not visible):
Piston and piston head:
Piston teeth. Note the last tooth is metal:
Piston head. It looks vented, as there's 4 holes on the sides. O-ring compression is OK, but getting a better O-ring (size #14) will improve compression a bit:
Cylinder with cylinder head:
I did note the selector switch assembly didn't have metal contacts on it, so it's different than the TM or aftermarkets' type. The CM031 probably uses a different selector switch assembly type than TM ones, so this part isn't interchangeable with aftermarket or TM parts.
IIId. BatteryThe battery provided, an 8.4v 1200mah Ni-MH mini battery, is actually a very good one (contrary to most China-made batteries I’ve seen). The manual claims it’s a Ni-Cd, but I’ve shot 1000rnds through it, left it over for 3 nights, and then shot another 500rnds before it died out. I haven’t used the provided charger yet, since I don’t have a power converter, I just used a US mini charger and it charges just fine. Normal charge time for the battery with the provided charger is 4-5 hours. The problem with the battery is that it does have a somewhat minimal capacity. In the middle of one of my games the battery just died out after about 1200-1500rnds. I do suggest getting a battery with a much larger capacity, but the connector in the stock won't work with large connectors without an adapter (~$3) or modification.
Here's a small mod I did: I yanked off the large male connector of a broken charger I had, stripped the wires, and attached the large connector to my rear wiring. Now the stock can take large batteries perfectly.
IIIe. MagazineThe magazine is one of the parts of the gun that is notably good compared to other CYMA hi-caps. The magazine is modeled after the ICS plum magazine, same on their AK-74. Even though the manual states the magazine holds 500rnds, I've counted and confirmed it holds 400rnds. The magazine doesn’t wobble when it’s in the magazine catch. After much testing I've found the mag doesn't jam or misfeed at all, which is very good for a CYMA-made magazine. I like the look of the magazine, but I’ve never been a fan of hi-caps, so I’m going to find some mid-caps to replace it.
IV. AccuracyWell, they're finally here: Tested w/ ITS 0.20g BB's, hopup set at halfway, rear sight set at 2.5. A little wind was present, so results may be a bit wrong.
25 feet semi auto:
25 feet full auto:
As you can see this gun is very effective close up, as with all AEG's...duh...
50 feet semi auto:
50 feet full auto:
From hear groupings get noticeably larger. I did hit all shots on target, but it became increasingly harder to hit it all on the bullseye.
75 feet semi auto:
75 feet full auto:
Now, the accuracy at this range was way off. I missed at least 2-3 shots on each trial, so I'd say the gun is capable of hitting a man-sized target at 80-85 ft, effectively.
I did manage to hit a trash can-sized target at 100ft, so the myth's of the horrible accuracy aren't completely true.
V. Performance - FPSUsing the Poor Man's Chrono, I've shot both a Sunkist soda can, and a regular Coke can, and the gun has managed to pierce through one side of the can yet leave a noticeable dent on the other side of the can. However, my gun did pierce both sides of a Sprite can (weaker aluminum?), so I'd estimate the FPS to be around 315-330fps w/ a 0.20g BB, depending on the quality of the internals of your gun. I managed to get some pictures of the test shots, so here they are:
Entry hole of Sprite can:
Exit hole of Sprite can:
Entry hole of Coke can:
Dent on other side of Coke can (a bit left of the "C" in "Classic"):
Entry hole of Sunkist Can:
Dent on other side of Sunkist can (on lower part of the "K" in "Sunkist"):
Another user, BLKKROW, has managed to get a video of a chronograph test at his local airsoft shop using a F-1 Chrony. His CM031 managed to hit 335fps w/ a 0.20g BB. Here's the link:
<![CDATA[<a href="http://www.youtube.com/v/xKSXlxJH43w&fmt=22&rel=1" target="_blank">http://www.youtube.com/v/xKSXlxJH43w&fmt=22&rel=1</a>]]> Va. Performance - Rate Of FireUsing the method suggested by Airsoft Mechanics (
http://www.airsoftmechanics.com/guides.php?aid=10), I used a simple microphone and Goldwave Audio Recording Software to measure my CM031's ROF. I fired a full 5 seconds of the gun on fully automatic. After this I zoomed in on the entire recorded sound session, then picked two points where the gunshot was recorded. The points I recorded shots were at:
2.5970 seconds
2.6680 seconds
Subtracting these two values yields a result of 0.071 second, or the time required to fire just one round in full auto. Then:
(60 seconds/minute) / (0.071) = 845.07 RPM, or 14.08 RPS.
That's pretty fast on a fully charged battery, comparable to a stock TM AEG, but this rate drops about after 400-500 rounds, as the ROF significantly decreases as the battery capacity decreases.
VI. Further External Upgrades + AccessoriesThis gun is decent all by itself (it's an AK!), but I'd prefer not to use the iron sights, as they are kind of inaccurate and very hard to aim with. Therefore buying a scope mount would be highly recommended. If buying a scope mount that attaches itself above the AK rear sight, then the screws underneath the receiver will hold the mount just fine. However, if installing a rear sliding scope mount (one used by real AK scopes and POSP Dragunov scopes), modifications may be required to install the slide onto the receiver itself. I'm not completely sure about this, but it may be required to drill two small holes on the left side of the lower receiver to let it be able to accept the mount. The AK-74M can also take other aftermarket external parts, such as stocks, handgrips, and tactical foregrips.
VII. ModificationsThis gun fires a very decent fps stock, almost higher than a stock TM AEG. If you want to keep it stock, then don't touch the gearbox; it's perfectly fine as it is. However, if you wish to keep the internal stock, yet want a longer lasting gearbox for the near future, then I'd suggest to replace the bushings (don't exactly trust them on any AEG clone) and do a re-shim job (the scratches on the gearbox shell support the fact a re-shim job is suggested). You can either replace the bushings with TM stock ones, but I'd suggest to get either Systema or Guarder bushings along with a Systema Shim Set, both costing a total of around $10-12. The V3 gearbox can take all aftermarket V3 gearbox parts, although I haven't internally upgraded my CM031 just yet. Regreasing the gearbox is also recommended, as I don't exactly trust the clear grease CYMA uses. I used normal hardware white lithium grease, which works perfectly. I'm betting the gearbox shell, like TM gearbox shells, can't take much pressure from the working of a stronger spring (like an M120), so a reinforced gearbox shell will probably be needed for higher level upgrades.
VIII. ConclusionOverall, this gun mainly surprised me by its quality. The build, the magazine, the hop up (almost as good as a TM hop up assembly), and the power all surprised me due to the fact it’s a CYMA gun. CYMA has definitely improved their name with the production of this gun, and can be stated this AK-74M is a full-fledged AEG. I’d say this gun is comparable, even almost better, than a stock TM AEG, and to quote nachosdesign2, “a generation ahead of all other AEG clones.” For now, I think it’s the best choice for an AEG, for beginner or veterans, for such a low price ($100-150 depending where you look) and of such good quality. I’ve not looked into the new DE, JG, Echo1, or SRC guns yet, but I can definitely say for sure, that this gun is definitely worth getting.
Pros:It's an AK...What else is there to say?
Very high stock FPS
Lot of metal parts
Very heavy
Upgradeable with all aftermarket internal parts
Able to take most external accessories
Excellent build quality
Good ROF
Good/Easily adjustable hop up
Pretty good accuracy
Magazine holds 400rnds
Magazine doesn't misfeed at all
Good quality battery
Cons:A bit front heavy (for some)
Hop up isn't as effective as TM hop up
Hop up assembly can't take aftermarket barrels
Selector switch assembly not compatible w/ aftermarket parts (selector plate too)
Possible reshim/metal bushing upgrade (not needed yet suggested)
Possible O-ring replace (not needed yet suggested)
Battery connector is mini sized, won't take large batteries without modification/adapter
Battery capacity isn't too high, may not last an entire airsoft game (~1200rnds)
More pictures:
The selector switch. Top is safety, “AB” (middle) is full-auto, "OA" (bottom) is semi-auto.
Enjoy the review!
