DIY - Fix leaking GBB mags. (with pictures - 56k beware!)

[Coresair]

Sorry to necro.

I just found out that my two TM MEU mags had developped leaks. I own a AA R27 (TM MEU clone) and my original Army mag blew within the 1st week. I just finished using the gasket maker on them. I have a game planned on saturday the 10th of july (we are the 6th today). Right now it is about 25-30 degrees (+ humidity) and I will let them sit untill saturday.

I will report on this sunday (the 11th)

[coach]

Just to add (and to bump for the people too lazy to search :P)

This method has now been done with the following mags:

TM G17 3rd gen
HFC G17
WE P14
WE stanag
TM MK23 Socom - safety valve disabled (removed and filled) so a bit more involved
KSC MK23 Socom
Maruzen p99
WA 8045 cougar
KSC HK USP Compact

I have only had to redo a couple of mags. TM G17 and TM mk23. The g17 was because I didn't clean all the oils out and the mk23 was because I didn't use enough sealant.

[Wildlife]

I've also successfully used this method on KJW G23, WA M84F, & TM Desert Eagle mags.
Haven't had to redo one yet.

[Armed Infidel]

Coachster

Outstanding post...will give it a go on a couple of my problem leakers.

[pewpew]

Thanks coachster!
Just wanted to confirm that this works with long hi capa mags as well. I let it cure for 3/4 days and it is great. Washing everything with light soap and water probably helped a lot. I dipped everything in a pot and the water afterwards was very dirty.

[CerberusNet]

I'd like to add the a few..
KJW M9
Luger(Not 100% on make)

Thank you for creating the thread Coash, and CDN. This may be an open door to many GBB solutions and is VERY effective.

[byblos]

Thank. You!!!! works great

[coach]

anytime

[Azathoth]

THanks for Necroìng this because I wasnt going to do it. I stopped doing this fix as I have found that the sealer doesn`t stay inside the mag. Once you screw down the base plate of your magazine it`s impossible to control what is happening with the sealer inside. I have found that the stuff flakes off and is ejected out of the nozzle and into your GBB internals which is mightly aggravating.

Instead I do a combation of finding new O rings, JB weld, and Teflon. I try and avoid doing this if at all possible.

[CDN_Stalker]

That is why you have to leave your mag sit completely empty for minimum 24hrs, had the same thing as you happen after I filled and tried about 12hrs later, was a bitch to clean up the internals and barrel. Outside of that one occasion, the dozens of mags I fixed with this trick worked perfectly, mine still do, and haven't heard anything from those whose mags I fixed as well.

And there is nothing wrong with necroing a useful fix thread, brings it to the attention of new members.

[coach]

Just to add to what stalker posted,

You didn't do step 12!

I pressurize, ever so slightly, to help prevent too much sealant from slowly oozing inside. But after it'd cured, I also fully gas it up and vent the entire mag inspecting for bits of extruded sealant.

I've had a couple with too much sealant inside so eventually became aware of where and how much I put in.

Of the mags that I've had leak again, it was only because of rough careless use dropping them on hard surfaces which changed the shape of the mag so the floor plate didn't seal anymore.

[Varjeal]

This may not be the right place for this but I have a question about something said in the original post:

"It also will work for the TM MK23 Socom mags but I would suggest removing the safety valve, JB weld the hold and then follow the procedure below."

Could we possibly get some pics and pointers on how to do that? Of three mags I own, the original one is already leaking after less than 200 rounds, so I guess its time to get some practice in. Also, it may sound silly but is it really safe to remove the safety valve and what's the purpose of it if only some mags have one? Thanks for any help and consideration.

[coach]

Originally Posted by Varjeal

This may not be the right place for this but I have a question about something said in the original post:

"It also will work for the TM MK23 Socom mags but I would suggest removing the safety valve, JB weld the hold and then follow the procedure below."

Could we possibly get some pics and pointers on how to do that? Of three mags I own, the original one is already leaking after less than 200 rounds, so I guess its time to get some practice in. Also, it may sound silly but is it really safe to remove the safety valve and what's the purpose of it if only some mags have one? Thanks for any help and consideration.

Yes it is safe. The pressure with propane exceeds that of the safety valve. Removing it bring the mag on par with all other green gas/propane mags. Your pistol is more than adequate to handle propane with proper maintenance, care and usage.

Anyway, once the safety valve fails due to propane over pressure, it will not close and continue to leak as if you drilled a small hole in the side of the mag.

I don't have pics and I'm on my phone so the following will have to suffice for now.

Remove floor plate and look for the half pin. It will be between the two retaining pins on one side only.
Drill it out with an appropriately sized bit. Avoid drilling too deep or on an angle. You only need to go as deep as the outer casing of the mag.
Remove the other two retaining pins.
Sand/file the stump of the half pin flush. If you drilled too deep, you can fill it with a bit of JB Weld later on.
Locate the safety valve and spring and remove both. Shake them out or use needle nose pliers or a small screwdriver.
Clean the opening of all lube a dirt/grim.
Mix your JB Weld as per the directions and fill the hole. Fill your drilled hole at this time if required.
Let dry overnight.
Sand your filled hole(s) flush and test fit it in the mag shell.
Continue with the sealing instructions as above.
Go shoot some baddies!

[lyphe]

Followed directions and it worked like a charm on my HFC M190 mag! I waited 48 hours just in case. Thanks!

[Gunny1980]

@coachster - You Sir are my hero! Tried out your method on my leaking KJW P226 mag and it worked flawlessly. Thanks again!