Breakdown Guide, Upgrade Guide, and Review of CSI AK47 Assailant

- Introduction
- Breakdown Guide
- Review
- Upgrade Guide
- Results

A few months ago I bought the CSI AK47 Assailant, thinking it was an ICS brand AEG. When I found out the truth, it explained why the price ($150.00) seemed incredible for an ICS AEG. Oh well, live and learn. It turns out that the gun is actually manufactured by CYMA, and it appears that JG sells the same gun under the name SVD AK47 (recently I have seen sale prices of less than $100). Both guns are inspired by the Dragonov sniper rifle design and therefore enjoy a visual aggressiveness that attracted me to the gun in the first place. The gun turned out to be relatively decent and, at least for me, it was worth the price.

It went to a couple skirmishes and held up pretty well. The high capacity magazine that came with the gun had feeding problems from the beginning. However, the drum magazine that my son uses on his ICS AK74 fit on the Assailant and worked very reliably feeding bbs into the gun.

Supposedly, the Assailant has a version 3 gearbox so I hoped that would lend itself to some moderate upgrades for the sake of performance and reliability. My upgrade goal for this gun was 375 to 400 fps, reliable 15 rps rate of fire, and reasonably accurate at a range of 150 feet. The point of this exercise is to see if I can upgrade this MPEG into a reliable and accurate AEG that has the range and accuracy of a medium powered sniper rifle and the ROF and punch of a poor-man's SAW. And to keep the upgrade costs less than what I originally paid for the gun ($150).

For all following images, click the photo to see the full size version, then click the back button to return.

Step 1 – Remove battery cover and battery.

Step 2 – Remove flash suppressor by counter rotating suppressor. Undo setscrew on the front sight and remove from barrel. Undo setscrew on bipod and remove from barrel.

Step 3 – Undo set screw on the gas tube molding and remove from barrel. Forward handgrip should slide off easily.

Step 4 – Undo screw on bottom of handgrip. Pull stock off, being careful not to stress motor wires.

Step 5 – Pull back on hop-up access bolt to reveal small screw at the forward end of hop-up slide. Undo screw and remove the screw and small plastic piece. Make a note of its orientation for reassembly. Undo small screw on left side of cover. Disconnect rod from the battery cover button and lift cover off gun.

Step 6 – Undo screw and screw-barrel key from left side of barrel. Pull outer barrel off inner barrel. Be careful not to bend inner barrel.

Step 7 – Undo four screws from bottom of receiver. Carefully pull barrel, forward receiver, and hop up assembly forward and apart from rear receiver assembly. Be careful not to lose the spring on the right side of the forward receiver. It fits into a slot.

Step 8 – Remove fire selection lever. Pry off screw cover and undo screw. Keep track of the bushing, screw, washer, and selector key. Carefully pull gearbox and motor from the rear receiver.

Step 9 – Undo two screws at the rear end of the hop-up assembly. Pull the hop-up and inner barrel back through the forward receiver.

Step 10 – Remove hop-up clip from the bottom of hop-up assembly. Firmly but carefully pull inner barrel and hop-up rubber out of the hop-up assembly.

In order to change the inner barrel, pull off the hop-up rubber and the small gold ring from the stock inner barrel. Put the ring on the new barrel and be sure you put hop-up rubber on so that the tiny ridge inside the rubber guides along the groove on the bottom of the barrel. When putting the inner barrel back into the hop-up assembly make sure the tiny groove is facing down and when the flat grooves on the side reach the rear edge of the clip slot the barrel is in far enough. The hop-up clip should securely click into place.

Reassemble gun by following the disassembly procedure in reverse order.

My initial reaction to the CSI AK47 Assailant was there sure is a lot of plastic used in the external components of the gun. The stock, forward handgrip, and the forward and rear receiver housings are all plastic. Since I am mainly used to Classic Army construction quality there was a definite sense of lower quality. This did not surprise me very much but I feel like I have to be more careful not to abuse the gun while in battle. Under severe cold or hot temperatures I worry that tolerances between plastic parts could suffer. However, all of this plastic does keep the weight of the gun down and makes it easier to carry.

When I disassembled the Assailant I found, under the long outer barrel, a regular AK47 length inner barrel (~450mm). The outer barrel does have a nylon inner sleeve that should provide a nice smooth surface to help stabilize the bb even more before it leaves the end of the outer barrel. The metal outer barrel is thin cheap pot metal and the paint is easily scratched off. I made several inadvertent scratches from removing the, sight, bipod, and gas tube molding.

The bipod is not impressive but it is serviceable. There is a metal clip that holds the spring loaded legs together and it was very difficult to unclip the legs the first two or three times. There is no adjustability in the bipod.

The magazines that came with the gun have not been very reliable. The high-cap magazine has serious feed problems. It does accept other magazines and I had better results with better magazines.

From the first look the gearbox appears better built than I expected and it is indeed a Version 3. Before opening it up I could tell that the bushings are plastic and the selector plate is nylon plastic as well, instead of polycarbonate. The wiring and gearbox external finish look good. I don’t recognize the motor brand (Chaoli) and any information on the label got messed up when pulling it out of the receiver.

The gearbox internals were not as impressive as the external first impression. There is a lot of nylon plastic parts inside, including the tappat plate, spring guide, cylinder head, piston, piston head, trigger switch mechanism, and nozzle. The cylinder has a vent hole that is more suitable for a barrel that is less than 250mm instead of 450mm. I found this a big surprise. Either the wrong cylinder got installed accidently, or they designed the wrong cylinder into the gun. On a positive note the gear set is quite impressive except for the anti-reversal lever. The gears appear to be made out of steel. The anti-reversal lever is a two-piece affair that seems flimsier than the one-piece levers I am accustom to.

The following pictures illustrate the disassembly sequence of the gearbox.

Be very careful when lifting the gearbox shell off. Hold down the cylinder through the gearbox window or insert a screwdriver into the spring guide and apply pressure so that the spring doesn't shoot the guide across the room.

My original upgrade plans were:
1. Replace the 450mm inner barrel with a 550mm Star tight bore (6.05) ($29.99)
2. Install new SRC steel gears ($29.99)
3. Install Matrix regular pitch M110 spring ($11.99)
4. Install Guarder Bull bearing spring guide ($17.99)
5. Install Guarder polycarbonate ventilated piston head ($16.99)
6. Install metal bushings ($5.00 paid to son for leftover bushings from earlier upgrade)
7. Install Systema Area 1000 Polycarbonate piston ($15.99)
8. ICS shim set ($4.99)
9. Paint imitation wood stock and forward handgrip black ($3.00)

Total cost = $153.93 (includes shipping)

Replacing the original 450mm inner barrel with the new Star 550mm tight bore was fairly straightforward. I did find, however, that the overall diameter of the new barrel was a fuzz hair larger and pushing it through the nylon sleeve was harder than expected. A little silicon oil helped solve the problem.

As I stated earlier, when I opened the gearbox I was surprised by how many plastic parts were used. It also surprised me to find a cylinder that didn’t match the barrel length. After taking a survey of the situation and consulting my spare parts bin I altered the original plan for upgrading the gearbox.

The executed upgrade:
1. Replace the 450mm inner barrel with a 550mm Star tight bore ($29.99)
2. Install Matrix regular pitch M110 spring ($11.99)
3. Install Guarder Bull bearing spring guide ($17.99)
4. Install Guarder polycarbonate ventilated piston head ($16.99)
5. Install Systema Area 1000 Polycarbonate piston ($15.99)
6. Install metal bushings ($5.00 paid to son for leftover bushings from earlier upgrade)
7. ICS shim set ($4.99)
8. Paint imitation wood stock and forward handgrip black ($3.00)
9. Install Guarder cylinder head ($18.00)
10. Install solid cylinder (spare part from an earlier upgrade project)

Total cost = $141.94

I decided to keep the stock gears, tappat plate, and nozzle. By re-shimming the gears along with the metal bushings I feel comfortable with the durability of this part of the gearbox. In the process of installing the bushings I did find the bushing holes to be rough and in need of filing. I did not have replacement parts for the tappat plate and nozzle. The tappat plate worries me the most from the standpoint of gearbox failure or malfunction. The nozzle is serviceable but eventually I will replace it for a better air seal.

After reassembling the gearbox I reach a moment of truth. From reading several other accounts of upgrading MPEGs I was concerned that the stock motor may not have the proper torque for pulling the stiffer spring. This problem seemed to be a common occurrence. However, the stock motor had no problem firing the upgraded gearbox. The sound and feel of the gearbox firing was strong and smooth.

As you can see in the pictures the visual results of the modifications is quite pleasing. The flat black stock and handgrip really add to the aggressive styling of the Draganov.

Testing for durability or accuracy has not started yet but the initial performance results are quite exciting. The first five shots through my chronograph registered at: 401, 399, 403, 401, and 398 fps using .20 bbs. With no hop-up dialed in the bbs were going well over 100 feet before diving down.

Approximately 50 to 75 shots have been fired with the upgrades and there does seem to be an intermittent feeding problem. It may be the magazines I am using.

There is an airsoft event on January 6th that I plan to take the gun to for field-testing, and accuracy tests will be conducted prior to that. When those results are available I will amend the review.