KWA M9 magazine problem

[God]

Hi, my KWA M9 PTP mag is, for some reason, unable to get more that 9/10 of a mag out before running out of gas. My other mag can fire 2 and a half full mags of bbs before emptying. Why? How would I look for leaks? It seems the broken mag expends WAY more gas than the other. ie, when I fire it, I feel gas coming out the back. In my other, I don't. Any ideas?

[Switchback]

To check for leaks, fill it up and listen to it for a hissing noise.
Either do that or fill it and place it into a ziplock bag, and wait about an hour. It will expand if there is a leak.

I do not have the most in depth experience with GBBs, but it sounds like your flow valve is letting out too much gas when the striker impacts it in the magwell.

[Jester316]

Do the bb's travel the same distance?

Have you tried using a different tank of propane/green gas?

Have you done any disassembly?

Where do you feel the gas "coming back out"?

[Switchback]

Where do you feel the gas "coming back out"?

When I had my HFC M9, there was something wrong with the blowback chamber, so when the slide blows back, gas comes out the back (the bottom below the safety) and you feel it on your hand.

I think that is what he is talking about.

[Jester316]

How about we let him answer the question? The PTP M9 is different than an HFC M9.