Sealing Leaky TM M9 Mags

[paradoxum]

So my 3x standard M9 mags began leaking propane from the baseplates. At first I tried silicone, no dice, teflon tape, no cigar, then found things like this:

And various forum topics elsewhere about using gasket sealant to fix leaky mags.

I bought this stuff: https://www.amazon.co.uk/gp/product/B00XLO2R2Q/ let it set for a week, filled the mags - nice! no leaks!

This morning I decided to chrono the gun, after emptying 1 mag I noticed black shit inside the barrel..

It's also inside the loading nozzle.

I filled the mag back up again and pushed down with my thumb, and this is what came out..

Absolute disaster. I'm going to disassemble them all and clean them up, but I don't know what else to try. Is the problem that I used black gasket sealant instead of blue? Has anyone done anything like this with success?

Thanks in advance.

 

[strykerles]

I tried clear silicon and bits came out with the gas when firing. Took ages to clean out, id like to know a solution too lol

 

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Why not simply replace the leaky O-rings with new ones?

 

[paradoxum]

Why not simply replace the leaky O-rings with new ones?

I'm not sure that would have done anything - at first I tried using well-applied teflon tape and 2/3 of them still leaked. They were actually all fine when I was using nuprol green gas, but when I bought a can of propane they started leaking the very first time I filled them with that.

 

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When my TM M9 mags started to leak I tried various things to recover the O-rings but ended up just replacing them. I can't remember what size I used though - I have a set of O-rings and just picked out a size that was about the same as the original and it worked fine. Lees Precision does a rebuild kit that includes base plate O-rings though: https://www.leesprecision.com/magazine-repair-kits-o-rings/magazine-rebuild-kits/rebuild-kit-for-tokyo-marui-mp9-magazines

I would also recommend running some maintenance gas or so through the mags every so often & leaving them filled with a little maintenance gas if they aren't going to be used for a while, to keep the seals in good condition - especially when using sniper gas/propane/CO2 and other such "dry" gases that don't have any silicone oil mixed in.

 

[paradoxum]

I'm in contact with a UK store that sells o-rings in large quantities - i'm going to send them a set of o-rings from the magazine and they're gonna measure them all for me and give me an invoice, there's a minimum order of 78 per oring which is like, £1, so I'm going to have hundreds spare - anyone reading this in future that needs M9 mag orings hit me up, I'm probably gonna put packs of them up on ebay for a few quid too as a side-gig.

 

[MadMole]

Silicon grease the O rings as a first try always. if you are using silicon or blue hylomar you don't need much and just put  a little on the old o rings. You are trying to seal minute holes, not a big gap

 

[Shizbazki]

I bought some of this stuff from ASDA or TESCOs once:

https://www.unibond.co.uk/en/adhesives/multi-purpose-repair/repair_extreme.html

It makes a clear, solid yet rubbery glue which i have found seals mags very well.

If you need to take apart a mag afterwards you just need to add a bit of heat and voila, you can take it apart again.

 

[paradoxum]

I did the whole thing again using *BLUE* RTV sealant, and also much less (I used way too much before) and each mag has been perfectly sealed since.