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

[klondike_bar]

I had a chance to play around with the G36k/e/ras systems today, great build. I cant speak to the gearbox or accuracy or anything field-based, but the materials, weight, and look of this gun are unsurpassed.

[kodokks]

Originally Posted by Basic-Wedge

Yes, velocity is under control, and the overhop has also been tamed.

The issue of the velocity being too high was easily resolved once I realized my G39 was one of the "Canada only" models, meaning it had been modified at the factory to shoot over 470 fps, in order to meet Canadian importation standards.

I tamed the velocity by fully closing the NPAS valve and by dropping in a small rubber O-ring between the valve and the two prongs on the back half of the bolt (looking at a disassembled bolt, that'll make clearer sense).

It's easy to know what size of O-ring to use - it's the same size as WE uses in the BB loaders they ship with their guns.

My G39 now fires .28s at about 280 fps, comfortably under local field limits. Since the rifle has all the range I need, and good accuracy. I'm leaving it set where it currently is. If I feel need for more velocity, I'll simply open the NPAS valve half a turn.

Hi, im new to this thread and new to g39. U're able to "tamed" the fps of your g39, BUT im trying to increase my g39 fps.

You said something about putting o-ring behind the 2 prongs on the back half to decrease ur fps. Could you please measure up your 2 prongs for me. The original size is 3mm high. I'm trying to figure out how many mm to cut the prong to increase my fps. and another request, could u please measure how far is the distance from the o-ring to the base of the prong?
(courtesy to some1 called badgi, thanks for the pic, he cut the prong 2mm and with original length from the o-ring to the base of the prong)

Thank you very much for your time.

[Ninja_En_Short]

??? x infinity

You want to increase your FPS ? Pardon the question but : how much does it shoots with 0.20g bb at 22/23°C ?
That thing is already powerful with a well known tendancy of the nozzle to explode (happened on mine too). So if it shoots at a proper speed already that's just a very short death sentence.

[XZIVR]

Originally Posted by klondike_bar

I cant speak to the gearbox

Neither can most of us.

[kodokks]

Originally Posted by Ninja_En_Short

??? x infinity

You want to increase your FPS ? Pardon the question but : how much does it shoots with 0.20g bb at 22/23°C ?
That thing is already powerful with a well known tendancy of the nozzle to explode (happened on mine too). So if it shoots at a proper speed already that's just a very short death sentence.

it shoots around 380 fps with 0.25 bb right now (npas fully closed), guessing its around 420ish on 0.20 bb. my g39c already using the g39k kit from ratech with 34cm 6.01 inner barrel and i installed an npas on the system, so i can always tuned it down when i need to.

well, i do this for knowledge n experimental purposes (especially after i saw the evi*& video showing 550ish on their "e" type.

Thanks ninja for replying...cheers

[Basic-Wedge]

Originally Posted by kodokks

You said something about putting o-ring behind the 2 prongs on the back half to decrease ur fps. Could you please measure up your 2 prongs for me. The original size is 3mm high. I'm trying to figure out how many mm to cut the prong to increase my fps. and another request, could u please measure how far is the distance from the o-ring to the base of the prong?

My G39 is packed away for the winter, so measuring the prongs isn't practical at the moment.

For guns intended for sale in the Canadian market, the prongs look similar to the image on the right. I would guess that's a little over 1mm. The rubber O-ring I used is the same size as the one used in a WE BB loader (when you disassemble the loader, you'll find the O-ring in the base). To accomplish my modification, you'd simply lay an O-ring flat across the top of the two prongs and reassemble the bolt.

If you have a standard style bolt and an NPAS valve, I would recommend you alter your fps by opening the NPAS valve, rather than filing down the prongs. Because of the short prongs in my bolt, I have to leave my NPAS valve closed at all times, just to keep the rifle within safe field limits.

FWIW, my experiences with the WE G39 have been so good, I've now ordered a WE M16A3 as my next project rifle. After using a GBBR for the tail end of 2010, I won't very often be using an AEG anymore.

[kodokks]

Originally Posted by Basic-Wedge

My G39 is packed away for the winter, so measuring the prongs isn't practical at the moment.

For guns intended for sale in the Canadian market, the prongs look similar to the image on the right. I would guess that's a little over 1mm. The rubber O-ring I used is the same size as the one used in a WE BB loader (when you disassemble the loader, you'll find the O-ring in the base). To accomplish my modification, you'd simply lay an O-ring flat across the top of the two prongs and reassemble the bolt.

If you have a standard style bolt and an NPAS valve, I would recommend you alter your fps by opening the NPAS valve, rather than filing down the prongs. Because of the short prongs in my bolt, I have to leave my NPAS valve closed at all times, just to keep the rifle within safe field limits.

Thanks basic. When u get the chance, could you measure it up for me. (distance from the o-ring to the edge/base of the prong and the length of the prong itself.) ps: i'm not talking about the o-ring u put to "tamed" down ur g39, instead i'm talking about the o-ring that actualy there on the back part of the nozzle, u can see it on my previous photo.

As for the npas, i believe fully closed position is where u get the highest fps, while fully open is when u get the lowest fps. And npas cannot increase ur FPS, the modification of the nozzle will. CMIIW

Thanks again people....cheers

[Sequential]

Originally Posted by jordan7831

Enjoy
http://www.boomarms.com/shop/item.cf.../curr_code/USD

You might as well pick up the HK sticker while you are at it.

http://www.boomarms.com/shop/showroom.cfm

The shipping from them isnt great but you arnt paying through the ass for a part you need.

Hey Basic-Wedge for the aluminum charging handle you bought did you have to do any modifications to the gun? or it fit perfectly

Thanks