TM G18C Issue

[frackz]

Hi everyone,

I have been trying to solve an issue with my TM G18c.

When the gun is fired there is virtually no blowback and hte round with roll out of the barrel or goes about 1-2ft. The next round also does not cycle.

This occurs when using standard TM Mags.

When using Long TM Mags the gun fires fine. and cycles. At time it maybe fire (no round) and you can hear the sound of gas been dispelled through the barrel. However majority of the time it fires fine all day on Long mags only.

It has been troublesome trying to disagnose hte issue. I have tried to upgrade the following parts and still the same issue persist.

AIP Metal Slide Release
AIP Steel Hammer Parts (includes all new springs)
AIP STEEL spring guide and spring.

I installed each of these one by one tested and still the results are the same.

Anyone have any ideas?

Using propane\green gas.

[e-luder]

if i may entertain you:

sounds to me like you've got a gas compression issue. It's mainly cause by the magazine rubber (the rectagular air nozzle which the gass pass through on the magazine) being worn due to the loading muzzle grinding against it. When there is too much space between the magazine rubber gas route packing and loading muzzle, gas tends to escape before it even reaches the floating valve. or at least not enough gas to cycle the gun 'crisply'

I can only venture a guess that that is what is happenning here since the problem is only inherent in one magazine. there are myriad of fixes but here is a few.

since your long magazine works, try swapping the magazine rubber with the short mag that doesn't work and see it fixes the issue. then you know you have found the issue. the you'll know what to replace or what to fix.

another way you can fix this is by shimming your bbu with duct tape. put some on top of the bbu so that you bring the bbu closer to the magazing rubber gas route thereby eliminating the uneccessary gas discharge and directing the gas directly into the Nozzle. dont put too much tape though. if you do, you cause the bbbu to be too close to the magazine rubber and wear it down even further. And also, the guide rails' path will be blocked by the bbu and the slide wont cycle at all. also the loading arm on the nozzle will jam the gun if there is too much tape.

the second thing is to disaasemble the bbu and see if anything is broken or worn.

[frackz]

E luder thank you for your message

I have decided to sell off my mags, and my gun as a parts gun (just broke my selector switch (did not notice the little nub)

thanks and I will keep this trick in the back of my head for next time.

I am going to guess it was not the rubber and maybe the shim only because one mag is used. The other two are brand new and did not catch right out of the box. So the rubbers should be good unless they are a different size or thickness on the long mags?

[e-luder]

In theory,

since one mag doesnt work and the others do, i would try to switch the rubber of the not working one with ine of the working BEFORE you shim it. that way you'll know for sure.

the rubbers should be the same on all the glock mags.

[shootersaber]

standard mag has issue, but long mag is no problem. I can said it is mag problem.I think it is the standard output valve or mag rubber issue. change them for test.