Leaky KJW M9 Mag
 

Hey all, I recently bought a KJ Works M9, have gamed it once, as a backup, and had to use it once. I've test fired a couple mag's worth, but it definitely hasn't seen much use. Well, I was heading out to a small skirmish today, and when I tried to fill the mag up, I found out that it was leaking. It sounds like it's coming from the filling nozzle, but i'm not too sure. Anyone know how to fix this?

Take the bottom off (you'll have to punch out the pins), oil up the seal or replace it with a new oring and put it back together. Most likely the main seal is leaking. It's very common with KJW mags.

For some reason, the KJW mags come from factory with a o-ring that is not the proper size for the seal needed.

I always upgrade mine with thicker ones.

Alright, thanks alot guys, i'll give that a shot. :)

I'm not sure if this mag has one or not.. but with my P226, I just tightened up the hex bolt and that fixed everything.

This does not apply as only the very earliest KJW mag designs cloned the two-piece mags that TM has. After those first releases, all KJW mags became one piece designs that are technically an improvement but they do not have hex bolts. They are held in by pins. The only solution for leaks is to thicken the primary o-ring. Some people have done this by adding thread underneath the original o-ring and filling it with silicone oil. Others use silicone tape. I found both methods quickly fail. I threw in an oversize o-ring and it solved the problem since it's much thicker than the stock one. I can't say what size it is though, I just found them via trial and error in a box of assorted o-rings I bought but they are not labled.

Some people don't even bother. I've heard of GBB gundocs that just use sealant and fuse or glue the two parts together. I'd rather do the o-ring mod since another issue you can commonly get is the metal tube that feeds the gas into the mag can come loose. If you glue the mag together and that piece falls out inside the mag - you are screwed.