Troubleshooting gun not firing M11/9

[hbar314]

Out at the range last night with the M11/9 with the Max 31 mk2 upper on the gun.

GF sets the gun down while shooting, just taking a pause. Picks the gun up after a minute to shoot some more and trigger doesn't do anything.
Hands it to me and sure enough, bolt is back, no jams in the chamber and the trigger doesn't really move or do anything.

Go to switch from smg to semi and the selector wont' budge.
Try to take the upper off and won't come off.

Made sure no cartridges were in the gun and pack up and leave the range.

When I got home I finally got the upper off, seems like the leg of that one spring should be under the part its above but figured I would post some pictures and ask for help from the community on what may be wrong.
Any parts that I should replace to make sure it doesn't happen again, or that look worn?

This morning I put the upper back on, bolt cocks fine, then trigger doesn't do anything and the upper seems stuck on the lower again...haha, ugh.

 

[strobro32]

The upper part of the trigger spring should hook under the left side of the disconector or the disconector will not hook on to the sear.

 

[bigmacster]

The spring is on top of the arm on the disconnect. The thing in the picture Strobro just posted. It needs to be hooked underneath.

 

[Captain murrica]

Great info found at http://www.mac-11.info/ hosted by forum member Concorde. Detailed breakdown/takedown directions and pics.

Fcg page http://www.mac-11.info/fcg.htm

 

[strobro32]

I've never seen that happen before. Be sure these guys are not sitting next to you at the range.

 

[hbar314]

Oh man, thanks for the helps guys!
I totally forgot about mac11 info.

Any idea why it might have come off the disconnector? Maybe the trigger spring needs replacing?

That did the trick!

 

[ScottinTexas]

GF broke it.

Your super intellect fixed it.

Use this to your benefit when the time is right.

 

[yzfchet]

I took a hard look at that on mine. The portion of the trigger spring which does a 90 degree bend upward to sit just forward of the disconnector could allow the disconnector to be forced over the top of the spring end if the length of that vertical spring stub was (maybe) only 1/32 inch shorter.

On mine, there is more than 1/16 inch of trigger spring stub rising above the level of the disconnector rod when sitting idle; it's level with the top of the sear. If yours is level with the top of your sear then it must have been gremlins as strobo32 suggested, or someone dis-assembling then re-assembling incorrectly your fire control group while you weren't looking. If it isn't sticking up that far, then you may want to replace your trigger spring.

 

[TheColtCollector]

How many of us here have the lage Full auto only trigger? Much more simple and couldn't exhibit the problems seen here

 

[hbar314]

GF broke it.
Your super intellect fixed it.
Use this to your benefit when the time is right.

She said the 31 upper config was heavy. I told her I'd get right on that and make sure to pick up an 11k upper to ease her burden.

I took a hard look at that on mine. The portion of the trigger spring which does a 90 degree bend upward to sit just forward of the disconnector could allow the disconnector to be forced over the top of the spring end if the length of that vertical spring stub was (maybe) only 1/32 inch shorter.

On mine, there is more than 1/16 inch of trigger spring stub rising above the level of the disconnector rod when sitting idle; it's level with the top of the sear. If yours is level with the top of your sear then it must have been gremlins as strobo32 suggested, or someone dis-assembling then re-assembling incorrectly your fire control group while you weren't looking. If it isn't sticking up that far, then you may want to replace your trigger spring.

Mines for sure not level with the top of the sear. I think that'd be the culprit. I'll put a new trigger spring in.

Who stocks OEM parts?

 

[Concorde]

Who stocks OEM parts?

Lage, on this page:
http://www.max-11.com/M11Parts.html

 

[hbar314]

Thanks!

 

[JohnFreeman]

She said the 31 upper config was heavy. I told her I'd get right on that and make sure to pick up an 11k upper to ease her burden.

Very well played sir!

 

[JackBlundell]

How many of us here have the lage Full auto only trigger? Much more simple and couldn't exhibit the problems seen here

I have one and I love it! I removed the trip to improve my gun's reliability. Once I did that, there was no point in keeping the OEM fire control parts. The Lage competition trigger is simpler, more reliable, and has a lighter pull than the OEM setup.