"This is my follow up gearbox review on the gun. After figuring out how to remove the gearbox and go into it, I can give better internal internal info on the gun. Starting with this... The gearbox shell seems to be good quality, some kind of standard black painted metal that mostly all gearboxes are. The gears are standard but strong, I'm pretty sure that they're 18:1 ratio or something standard like that. The piston is a standard CYMA one, being made out of a durable polycarbonate material, it only has one steel tooth but it's still strong nonetheless. The piston head is also polycarbonate, is decently ported, but mine had a rather small o-ring (which results in not so great compression between the piston and cylinder). You can stretch it out over something to make it bigger, or just go with a #14 o-ring which can usually be found at a hardware store. The silver cylinder is excellent quality, being made out of steel I think, and it is not ported. The cylinder head is a standard polycarbonate CYMA one, has ok compression, and has one o-ring. The air nozzle is the only kind of sub par component in the gearbox as it's some kind of clear polycarb material and doesn't have an inner o-ring, but an upgrade one can be bought for like $8 or something. The spring guide is a strong metal and has 3 bearings on it, which makes it rather hard to push the spring back in. The spring is a stiff M120 which can also be hard to push back into the piston when reassembling. The anti reversal latch, tappet, tappet spring, trigger set, and trigger springs are all good quality, and don't need any upgrades. Oh, and the trigger contacts are ok, I haven't really messed with those much and I think they'll be fine.
Overall, all I would really recommend upgrading would be the air nozzle for better compression and durability, and maybe a weaker spring if you want to have an easier time reassembling the gearbox. I bought an M110 Matrix spring, and I must say that it's even stiffer, longer and harder to put back in than my stock M120, you may want to go with like an M100 of a different brand for a spring downgrade. You may also want to re shim the gears, which isn't really all that hard, and re grease everything with Teflon grease to make everything run smoothly. So that's my run down of the internals, they're overall very good for the relatively low price of the gun, and they need little to no upgrades. They should do you well and perform pretty well, CYMA VFC clones are the way to go. Hope this helped...
"I got this gun about a month ago, and I must say that it performs pretty darn well for the low price of $136. The best feature about this gun are probably the externals; the metal is mostly steel, with nice quality polymer hand guards and a polymer motor grip. Hits pretty hard with .2s, about 390-410 FPS; with .25s, the FPS is like 370-385. Stock, the accuracy is pretty nice and can probably go to about 150-170 feet accurately in regards to hitting a man sized target, maybe even a little further idk. The stock mag isn't bad, feeds well, and has a nice finish to it. The gun itself is fairly compact, and still has a decent length ~400mm stock inner barrel. The folding stock is also steel, durable, and the hinge/latch that holds it in place is pretty strong as well. My main issue with this gun is that the V3 gearbox seems to have been jammed in really hard into the lower receiver of the gun, and it doesn't seem to want to come out, although it moves up and down if you push/pull on it. Idk, it may just be my gun, I don't know if this is standard for all AKs, it may just be a thing of applying more force to the gearbox.
Upgrades I made to this gun are simple things just due to my gearbox not wanting to come out easily, which include G&G Green Bucking, a Matrix 370mm 6.03 inner barrel, and Angel Custom H-Nubs. The gun is very accurate to about 150 feet with .25s, but then goes a tad to the right after that distance. With the black H-Nub, the gun shoots very far to well past 250 feet, although it probably won't hit much effectively at this distance. I have not tried out the white (clear) nub yet, as this one is claimed to offer better accuracy over range.
-Excellent externals, especially for the fairly low price
-Metal hop up unit (Zinc Alloy I think)
-Folding stock that won't break on you or snap off
-Rather compact, M4 length, but still has a good sized ~400mm long inner barrel
-Pretty accurate and has a good range, although the bbs seem to curve a tiny bit to the right after about 150 feet.
-Shimming seems alright, doesn't sound like a train screeching its wheels when it's shooting.
-Unique look for an AK, sets you aside from the vast sea of M4s.
-Balanced weight, does not feel front heavy and weighs less than my brother's AK-74u
-Since it's a VFC clone, not Tokyo Marui, the take-down is not that hard to do, and is quite alright once you've figured it out.
-DOES NOT come with battery, buy a stick type for this.
-Came in some lame box without any marking or labels or zip ties, but this is hardly a con lol
-My gun's gearbox seems to not want to come out of the lower receiver, hopefully I can fix this in the future.
-Stock wobbles a bit from side to side, but it isn't too noticeable, is to be expected, and isn't really much of a con.
-The sights kinds suck imo, but that's standard with all AKs, and a scope mount+red dot should make aiming easier
-Hard to understand manual it comes with lol.
Overall, this is a very nice gun that will serve you well and make you happy to own it. I would strongly recommend this gun as a beginner or intermediate gun. If you are to do upgrades, do them wisely, and you will be very content with this gun.