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Brand New Broken Gun. Help Me!

Broken Break Flaw Problem Automatic LM4 MAGPUL PTS Leak Gas

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#1 paulle

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Posted 03 May 2013 - 02:51 PM

Hello!

I recently purchased a brand new KWA LM4 PTS MAGPUL EDITION, I am new to GBBR's and to this forum.

Whenever I shoot my KWA LM4 PTS MAGPUL EDITION, with the provided PMAG, on full automatic, filled with King Arms SOFTAIR GAS, and filled with 38 KWA PERFECT 0.25 g SUPER PRECISION BB's, the gun will shoot about half of the rounds in the magazine, then it will stop shooting half way. At this point, the bolt will be stuck, at about the half way point, and gas begins to leak from the magazine.

While shooting the gun on full automatic, I am holding down the trigger until the problem above occurs. I understand that doing so is not good for the gun, but the gun should be able to perform the task above without any flaws. After the problem above is resolved, I will switch to shooting the gun on full automatic in bursts.

What I normally do is pull the charging handle back, and the bolt will slam to the original position by itself. If there is any gas remaining in the magazine, which there really is not, the gun will shoot the round in the chamber with little to no velocity, but the same problem will occur repeat. The bolt will be stuck, at about the half way point, and gas begins to leak from the magazine.

Additionally, I hear the magazine hissing, and I am assuming that it is leaking gas, but I believe that is not the problem, is it?

This problem occurs repeatedly, and it really discourages, me, as I have very recently purchased this product solely because of the high reputation and reviews KWA and this guns have recieved. My gun proves otherwise.

If a video is required to properly demonstrate this issue, I will post one.

I hope somebody will help me, please!

Edited by paulle, 03 May 2013 - 03:05 PM.


#2 R_King91303

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Posted 03 May 2013 - 03:06 PM

Hi Paulle,

Congrats on your recent purchase. To start ruling out non-mechanical issues, I do have a couple of initial questions. How long are you charging the mags for? Have you tried testing with a different can of Green Gas?


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Edited by R_King91303, 03 May 2013 - 03:07 PM.


#3 netpoc

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Posted 03 May 2013 - 03:15 PM

Clean the excess silicone grease from the bolt and make sure the feed ramp and chamber areas are clean.
It sounds like with all the full auto shooting the green gas is freezing the bolt to the chamber via all of the excess silicone grease, not allowing free movement of the bolt carrier or the reset of the firing pin and release valve.

Edited by netpoc, 04 May 2013 - 07:07 AM.


#4 paulle

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Posted 03 May 2013 - 03:21 PM

R_King91303,
Thank you!
I am simply charging my magazines until I stop hearing the gas transfer into the magazine.
And, no, I have not triend testing with a different can of Green Gas.


netpoc,
Wouldn't cleaning the excess silicone oil from the bolt increase the chances of the bolt getting stuck?
And sorry, but what is a feeding ramp? I am very new to airsoft, let alone fire arms.
The chamber area? If you mean the hop-up area, the place where the BB sits when loaded and prior to shooting, and inner barrel itself, I have stuck an unjamming rod down there, but only to push out the last BB in the chamber because my magazines were empty of gas.

Hope this helps!

Edited by paulle, 03 May 2013 - 03:34 PM.


#5 R_King91303

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Posted 03 May 2013 - 05:29 PM

Since you are still relatively green when it comes to airsoft, I'd try a different can of green gas 1st. Over time cans of GG can loose pressure which can lead to the cycling issues with the bolt you are describing. Additionally, I typically charge each mag for about 30 seconds, under filling can also cause the issues you are describing. Also, even though it's a n00b point, make sure you are charging the mags with GG nozzle pointed down towards the ground and the fill nozzle stem on the magazine has a little o-ring rubber on it (it could have fallen out)

The fact that you are able to make it through half a mag before the bolt cycling issue manifests makes me think it's a gas pressure issue.


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Edited by R_King91303, 03 May 2013 - 05:32 PM.


#6 netpoc

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Posted 03 May 2013 - 08:02 PM

I thought the same thing when I got my LM4. The only thing that needs lube is the o-ring on the bolt/piston. Think of it like this; there are clearances that need to be there in order for the gun to operate properly. When that thick silicone grease gets into those areas and swells the bucking, closing those clearances problems such as what you are describing will arise. Yes the feed ramp and chamber is the area surrounding the hop up.

#7 Chuck S

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Posted 04 May 2013 - 06:01 AM

A weakly charged magazine can exhibit these symptoms.  I charge my LM4 magazines for 45 seconds each.  They can't be overfilled.

Don't rule out a bad magazine or one that needs maintenance.  The release valve has three (four?) O-rings and a small amount of dirt can cause the valve to stick and vent all the gas.  From notes here it appears that these valves will all eventually need to be removed cleaned, and lightly lubricated with silicone oil.

-- Chuck

#8 gcw360

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Posted 04 May 2013 - 06:42 AM

View Postpaulle, on 03 May 2013 - 02:51 PM, said:

Hello!

I recently purchased a brand new KWA LM4 PTS MAGPUL EDITION, I am new to GBBR's and to this forum.

Whenever I shoot my KWA LM4 PTS MAGPUL EDITION, with the provided PMAG, on full automatic, filled with King Arms SOFTAIR GAS, and filled with 38 KWA PERFECT 0.25 g SUPER PRECISION BB's, the gun will shoot about half of the rounds in the magazine, then it will stop shooting half way. At this point, the bolt will be stuck, at about the half way point, and gas begins to leak from the magazine.

While shooting the gun on full automatic, I am holding down the trigger until the problem above occurs. I understand that doing so is not good for the gun, but the gun should be able to perform the task above without any flaws. After the problem above is resolved, I will switch to shooting the gun on full automatic in bursts.

What I normally do is pull the charging handle back, and the bolt will slam to the original position by itself. If there is any gas remaining in the magazine, which there really is not, the gun will shoot the round in the chamber with little to no velocity, but the same problem will occur repeat. The bolt will be stuck, at about the half way point, and gas begins to leak from the magazine.

Additionally, I hear the magazine hissing, and I am assuming that it is leaking gas, but I believe that is not the problem, is it?

This problem occurs repeatedly, and it really discourages, me, as I have very recently purchased this product solely because of the high reputation and reviews KWA and this guns have recieved. My gun proves otherwise.

If a video is required to properly demonstrate this issue, I will post one.

I hope somebody will help me, please!
The hissing mag sounds to me like an indication that, even if you are filling the mag, it's not holding enough gas and therefore causing your issue.

If the shop where you bought the gun won't hook you up with a mag that is working (check with them), then you have two options for a leaky mag:
  • Send the mag in to KWA for repair, it has a 45 day warranty like your gun
  • Attempt to repair it yourself - I don't recommend this to anyone who is under warranty unless they have experience with the repair.  See Here for the tear down guide: http://kwausa.com/fo...249&hl= lm&st=0
Note: You will need the proper valve tool to loosen and re-tighten the valve.

If you decide to send the mag in for repair, please start a ticket through the Help Desk.

#9 -wigs-

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Posted 04 May 2013 - 09:43 AM

It sounds like your getting double feeds and just smashing them out by racking the charging handle. I do not recommend doing an rs rack, rack,rack to get the bolt home. There's no stuck brass and if it's a jam you could destroy your hopup or nozzle

#10 BoobieM4H

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Posted 05 May 2013 - 06:30 AM

Like Netpoc said..your freezing the rubber parts..orings on the nozzle and nozzle plug..in the the bolt..causing the nozzle to stick and when shooting it vents all the gas out the mag..letting your mag return to room temp after shooting it full auto is good practice..specially if you only own one mag.

( o Y o )







Also tagged with one or more of these keywords: Broken, Break, Flaw, Problem, Automatic, LM4, MAGPUL, PTS, Leak, Gas

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