WE G39C Problem. Bolt not locking back.

[Icebass]

As it says in the title I have a G39c. It fires flawlessly and doesn't skip a beat. I am currently running it on propane. My problem with this gun is that when I either insert am empty magazine and pull the bolt back or fire the last round in the magazine the bolt does not lock back. I have three mags for the gun and it does this for all three. Now I noticed that if I push the magazine harder into the magwell and hold it while pulling the bolt back it will catch.

I've already done a bit of looking into this and have tried the only three things that have been suggested. I have taken the gun completely apart and lubed it correctly. I have also tried tightening the screw on the bolt catch. I also found a post saying to put some rubber in the bottom of the bb holder in the magazine so that the spring would be compressed more and push the tab (that in turn pushes the bolt catch up) up harder. Doing all of these has not remedied the problem. So I was wondering if anyone out there has any idea what the problem could be?

Cheers for having a look guys.

[tisane]

How hard is it to manually push up the bolt catch from inside the magwell?

[Icebass]

Re: WE G39C Problem. Bolt not locking back.

Not hard at all, there's no resistance to it. Just out of interest I cut down a bit of sorthobane and glued it under the bolt catch. Now when I pull the bolt back it does lock back, but after i shoot the last round it still does not lock back. Which is making me think there is a problem with the bolt not moving back far enough?

[tisane]

Ok so that rules out there not being enough pressure in the feed spring to push up the catch.

My other thought was that there could be something wrong with the mag catch meaning that the mag was sitting lower in the mag well, your temp fix with the Sorbo would point to that too, however with the mag sitting lower in the mag well I would expect poorer gas consumption.

If you manually cock it with your mod does it hold back everytime?

Another thing I remember from my time using a G39 is that the part of the bolt that the catch caught on would wear over time, could that be an issue?

[Icebass]

Re: WE G39C Problem. Bolt not locking back.

The mag catch looks 100%, no wear. Also the bolt looks to be in perfect condition where the bolt catch locks into it.

When the mag is in and I manually cock it, it does lock back. But when I take the mag out the bolt comes forward again. Its as if there is something pushing the bolt catch down again. Could it be the spring on the bolt catch is too strong for it? Might take the whole trigger mech apart tomorrow and look at it. Thanks for the help btw.

[tisane]

There is a spring in the bolt catch mech that keeps the catch pushed down to stop it randomly locking back, but I don't see it having the strength to release the bolt when the mag is removed.

[Icebass]

Re: WE G39C Problem. Bolt not locking back.

Tisane thanks for all your help. I've got it fixed now. Basically the I had to file down the triangle bit of the bolt catch as it was not allowing the catch to engage the bolt properly. Its now engaging it properly and fully working. Woop Woop.