agm gbb m4 mag leak

[tom the bom]

how do you sort leaks out on these? i got the upper rubber bit off the top of the mag and everything else looks abit complex. could anyone give me some advice?

thanks

tom

[B.E.N.]

Re: agm gbb m4 mag leak

LeoDanger on here has one. It's a nightmare apparently. He's very good with mechanics and fixing, but he hasn't managed to get it to a point where it lasts more than a mag or so without popping.

Might be an idea to drop him a PM?

[LeoDanger]

Re: agm gbb m4 mag leak

You should grease the top and bottom o-rings, once it's disassembled, but I found that the outlet valve is junk. Changing that sorted mine.

Does it leak slowly really, or does it dump its gas in one go? If it's dumping, or won't hold gas longer than you can get it in, it's probably the outlet valve (WA style). Easy to change, once you've stripped the mag, but the upper assembly is a little fiddly if you're not confident.

Ai magazine did a guide to stripping gas mags a while ago – worth a look if you're going to try it. I've also heard that they're doing a guide to changing these exact valves in the future.

[tom the bom]

Re: agm gbb m4 mag leak

its a very slow leak, a gentil hissing

[muzzy]

Re: agm gbb m4 mag leak

have you found the exact place its leaking from (assume from your post its from the top only)

[vikerz18]

Re: agm gbb m4 mag leak

I just bought one of these agm gbb m4's. Havent recieved it yet but would like to know a few things. What other mags fit this gun? and where can i find good upgrade parts for it.

Regards

[muzzy]

Re: agm gbb m4 mag leak

agm mags are ok, bomber are good,pro wins are good, 5k etc

[LeoDanger]

Re: agm gbb m4 mag leak

Poking around the top won't fix a leak – that rubber piece seals against the bolt.

Once again, you need to open up the mag and grease the two large rubber seals (like big oblong o-rings). If you're lucky that'll fix it. You could well need a new outlet valve though.

Unlike Marui GBB pistol mags, there's not a simple screw to tighten, as the mag is entirely held together with pins.