[WE] G39C - H&K G36C for normal people

[Kit]

Originally Posted by Basic-Wedge

I just received my new WE G39K yesterday, and I really like what I've seen of it thus far. After many hours familiarizing myself with the rifle, installing upgrade parts, and firing it in an effort to tune its output, these are some of my initial findings:


Straight out of the box, this rifle is a monster!

In unmodified form, it launched .25 BBs at 425 fps, using Coleman brand propane, at 20°C. A follow up test, later in the day, using duster gas, saw .25 BBs averaging 295 fps, at 23°C. Back to propane, and with the RA-Tech NPAS valve now installed, velocities averaging 394 fps were observed under 27°C temperatures.

So far, all velocities achieved with propane are far in excess of our local field limits. To tame down to acceptable velocity, the rifle will have to output no more than 350 fps with .25 BBs (about equivalent to 400 fps with .20 BBs). I'd be happier with even more leeway, say about 325 fps.

The NPAS valve has velocities heading downward, but I'm going to have to develop a better comprehension of how it works in conjunction with the rifle's nozzle before I can properly tune the system. I don't know if the valve should be mostly opened or almost closed, or how much I should trim off the tabs on the G39's piston. It all seems a bit muddled at this point.


I've read that many users experience slight over-hop, even with the hop-up unit set to its lowest setting. I experienced that too, but solved the issue by removing the stock hop-up nub, and replacing it with an “H” shaped SCS, or “Shredder Concave Spacer”. The stock nub is noticeably thicker than any nub I've previously encountered – I'd say it's simply too thick for this application. Now, with the Shredder, I'm getting a beautiful, flat trajectory over huge distance.

While I had the hop-up system disassembled, I took the opportunity to apply a thin wrap of Teflon tape around the hop-up rubber and down the barrel about 2cm. I've noticed some users report this helps stabilize the inner barrel. In my case, I did it with the hope of forming a more airtight seal between the hop-up rubber and the barrel. In any event, it doesn't hurt anything, and it may even help.


A comment I've read often is that the barrel nut is on so tight, extraordinary means must be employed to remove it. On my rifle, I used a section of 1/8th inch flat steel as a makeshift wrench, inserted it into one of the slots, then carefully loosened the barrel nut. I would not advise using a flat blade screwdriver for this, as the blade will surely be too thin and the tapering will work against you. Using a flat bar of steel seems much safer.


Once I'd gotten the inner barrel out of the rifle, I thought it might be a good idea to run some cleaning patches through it. I'm glad I did, because it was extremely filthy. I used a dozen patches before I had it cleaned, and some of the first patches picked up specks of brass and other flecks of metal. The inside of the outer barrel also needed cleaning, as there was quite a bit of debris in there too. The stock inner barrel is a stout 34cm long 6.03mm tight bore, made of thick brass. RA-Tech makes a replacement 6.01 tight bore, but with getting velocities under control being such a daunting issue, I don't see myself ever wanting a barrel which will, again, boost BB velocities.


A popular modification recommended for the WE G39 is to replace part #125, listed as an M3x3 screw (a 3mm allen head screw, 3mm long) with a similar fastener that's 5mm long. Early production models may have benefitted from this mod, but my rifle came from the factory with an M3x5 already installed.


There are several parts changes I've made that I'd like to recommend to other G39K owners:

I replaced the WE aluminum flash hider with a Classic Army G36K flash hider made of steel. The CA unit is noticeably heavier, and I like the improved balance that extra weight provides.

I also replaced the original charging handle, made of reinforced polymer, with a CNC'd aluminum unit from NeBula. The two parts look absolutely identical, but the aluminum handle should stand up longer to repeated use. The NeBula came from Tokyo Model Company in Hong Kong and sells for $28 USD. To swap out the handle, all it took was the removal of a single pin.

I also installed a WE IdZ stock and top rail. The stock folds, same as the original skeleton stock, but is adjustable for pull, and has a cheek rest with three settings. The top rail is a simplified design, featuring folding back-up sights, which snap crisply up or down. I've taken advantage of the increased amount of available rail space, and mounted a clone 3.4x Elcan scope at the back end. I'm hopeful this robust unit will handle the rifle's fairly stiff recoil.


The only portion of the rifle I haven't tackled in depth is the trigger group. For now, I intend to check the entire assembly for loose fasteners, then lubricate it with Break-Free CLP, the synthetic lubricant of choice for all my firearms going back many, many years.

On the exterior of the bolt carrier group I've been happy using Phil Waterproof Grease, but I'm still searching for the right lubricant for the inner parts of the BCG. None of my usual choices have given me the smoothness of function I experienced with the original factory applied lubricant.


That's all I have to report at this stage. My G39K shows plenty of promise. I've made excellent headway on it so far, but I have to focus now on getting the velocity under control, so I can use this in local games.

Great review!

[Basic-Wedge]

I'm still trying to get my G39's velocity under control. Every other aspect of the rifle's performance is fine, but it's still too hot for use in games.

With the NPAS valve (turned three full turns CW) to wide open, velocity with .25 BBs is a smokin' 433 fps. Closing the valve (turning it CCW until it seats), and theoretically choking off the gas flow completely, only reduces velocity to 429 fps. It's like the NPAS valve has absolutely zero effect on the rifle's function.

I'm so confused...

Most other users report their guns have lower velocity, even with the NPAS valve set wide open, and they have to modify their nozzles by cutting down the two plastic lugs inside the rear portion of the nozzle. My gun seems to be the opposite.

Initially, I thought filing down the two lugs lead to reduced velocities, so I did that in my gun too. Now I'm thinking I should've left them alone. I see where some users instead remove the lugs completely and file notches across the top of the rear nozzle. If I've made a mistake by shortening my lugs, I can probably recover from that mistake by cutting notches into the rear nozzle.

Anyway, I hope that seems understandable. If you've ever torn down a G39, you can probably visualize what I'm dealing with. I'd just like to know if other users have had to overcome a similar issue.

Just as an added thought: On WE's website, they now list a "Canada Only" version of the G39, with velocity rated at 430+ fps (to get around Canadian importation requirements, I'd imagine). Also, Evike in the U.S. advertises a special high velocity version of the G39 (500 fps). I'm wondering if my rifle isn't like those two versions, and therefore producing greater velocity than models previously sold in Canada. If that's the case, I may have to install a different nozzle in order to get my fps down to safe levels.

[snipersyntagmatik]

This thread just won't die!

I'm glad there was a revival - always good to have more feedback and experience. Search, Search and Search!

Anyhow, update to all my previous posts in this thread...

The firing pin has finally been worn on my G39 since February of this year after a 2-3 games of SERIOUS use. As another poster mentioned, this parts would better be served had it been made of steel in the first place. Yes, it is made of POT CRAP and it has resulted in mechanism not applying the proper amount of pressure on the gas valve during trigger pull. So....

on to the ordering of an RA-TECH CNC steel firing bin base and valve locker.

Will update after order and install.

[jordan7831]

Can you do a how to write up on this? I want to do this as well but im not sure about taking the plunge on opening it up. Thanks!

[Ninja_En_Short]

Not only the firing pin, the whole trigger assembly is pure crap, that's why this model has lost my recommandation forever.
I will do a new review as soon as I get the VFC.

[dissolutionskey]

Did you ever find an acceptable replacement for your air nozzle? 4 rounds out of the box and i had a bb lodge in the top of mine and crack it. If you haven't found a replacement I will just have to machine one at work then i am just hoping someone has a solution because NO ONE has them in stock.

Thank you

[Ninja_En_Short]

In the end I couldn't find replacement anywhere but on the WE website.

I said it already but I'll say it again : the huge number of models is meant for locking the market, not improving on design and shamefully we're paying the price of it.

If you want a G36 GBBR wait for me to get my VFC this week and you'll have a review of the alternative

[jordan7831]

Originally Posted by dissolutionskey

Did you ever find an acceptable replacement for your air nozzle? 4 rounds out of the box and i had a bb lodge in the top of mine and crack it. If you haven't found a replacement I will just have to machine one at work then i am just hoping someone has a solution because NO ONE has them in stock.

Thank you

Evike has them but they are out of stock perhaps you can try to get the upgraded to the tits version that makes it 500fps and then somehow down tune it with an npas??

Anyways here is the linky

http://www.airsoftpost.com/product_i...ducts_id=35699

NINJA I cant wait for the write up on the VFC, hope the mags arnt as shit as the WE ones. Nothing a little permatex blue gasket maker cant fix though

[FinnFighter]

Hi!

I got my WE G36K a month backward or so. Since getting it out of the box, I've had problems with the weapon's hopup... I started with 0.28G bb's and it had a HUGE upcurve, about 10 to 15 cm from the barrel-line at a 2m range. I thought that the easiest solution is to get heavier bb's. Now I have 0,36G bb's and STILL I'm getting an upcurve... And yes, the hopup is adjusted to minimum. Another issue is the huge barrel wobble, but I saw the post about fixing it with epox, should try something similar..

So, any guesses on the hopup?

[Basic-Wedge]

The G39's hop up is very aggressive. I've partly tamed mine by dropping in a "Shredder" nub and by dialing back the velocity. It doesn't help that the standard bucking has a nub molded right into it. I suspect the ultimate fix will involve swapping out the bucking for one that doesn't include that molded piece.

[dissolutionskey]

Can anyone give me the I.D. of the air nozzle? mine is deformed so im going to maching a support for it but i need to know the I.D. of it to do so. Thank you

*edit* i managed to get the dimensions for it. I did it at work today and will post up some pictures tomorrow. Fixing the air nozzle seems to have fixed a lot of double feeding and jaming issues. Also due to less of an air leak my fps is up about 15-30 fps on a chrono.

[Basic-Wedge]

I have the NeBula aluminum charging handle, but I've just become aware of this one from X-Fire:

http://www.x-fire.org/we_gbb/g39/handle/e.handle.html

It looks pretty good. Maybe we'll see more parts from them in future.

[snipersyntagmatik]

Originally Posted by Basic-Wedge

I have the NeBula aluminum charging handle, but I've just become aware of this one from X-Fire:

http://www.x-fire.org/we_gbb/g39/handle/e.handle.html

It looks pretty good. Maybe we'll see more parts from them in future.

It's about time parts like this were being released.

Refer to earlier posts like #58 to gain more data on the charging handle assembly.

[kullwarrior]

That's really really pricy

Nebula one was $28+Shipping (probably $15 or so)
PDI is selling for $35+Shipping (probably $15 as well)
Real one from distributor is around $40

I know real one needs to mod to make it work, but there isn't any report of real one breaking either.

[Stocko]

Does anyone know if the charging handle from an AEG would work?