Bad first day at the range! - M11 + Max31

[tec9]

Hey all-
Last night I sent a similar email to Richard Lage, but thought I would also throw this out to the group to see if anyone had any suggestions.
Yesterday I was just approved for my M11 stamp (first machine gun for me!) I immediately installed the Max31 MK2 upper and went to my local range. I was so excited to pop my cherry on shooting full auto, but it did not go as planned ☹ I found out my Max 31 refuses to cycle properly. When a magazine is inserted, you can cock it, and it will hold the bolt back. When I pull the trigger, the bolt will strip off a round and fire it. It will then eject the casing. At this point it appears that the bolt gets stuck in the back of the receiver in the back position. Pulling the trigger does nothing, and I can only get the bolt unstuck by starting the process of removing the receiver. It’s almost like the bolt slams back in the receiver and gets stuck there. It did this 5 out of 5 times, so I figured something is very wrong. I also want to mention that this was in semi-auto mode. I first needed to zero in my red dot, so I didn't try full auto. Another bit of info is, that when I got home I briefly looked at it, and it appears that when cycling the action/ bolt by hand and it seems that it acts up when it is in semi mode. (full auto seemed okay when manually cycling) When it jams up, I also can't move the selector switch from SMG to SEMI. I’m not sure if it something in my lower receiver, or something in the Lage upper.
I am new to the M11, so hopefully I am explaining it correctly. Any suggestions on what the problem could be?

Thanks to all in this group!

 

[pmf]

Is it the M11, or the Max31? Did you try shooting the M11 in stock configuration? Might be that the gun is messed up, not the upper. Load 4-5 rounds in a mag and try it. Try it with a couple different mags -- it could be the mag you used. If you isolate the problem to the upper itself, contact Lage -- he's a solid guy who stands behind his products.

 

[tec9]

I did not try shooting the M11 in the stock configuration. The dealer I bought it from tested the gun and I was told that it runs fine. I only tested the one magazine I have for the lage max 31, but I do have drums. I’m not sure if it’s magazine related, because when I experience the jam, I can remove the magazine, and the bolt stays stuck in the open position. Pulling the trigger does nothing, and I can’t flip the switch between SMG and SEMI. The only way to get the bolt to get unstuck is to begin the process of the removal of the upper.

 

[Gaujo]

That Lage stuff is CNC machined, the mac, bent and welded sheet metal. If this is a new gun it may be dimensionally out of spec and have to be fixed, which people with NIB guns find from time to time. Def try the stock upper, but even if that works it could have potentially been hand fitted.

 

[nklf]

Is the safety loose? If the safety lever is moving into the safe position while the bolt is still forward it will lock up the bolt as described.

 

[Vegas SMG]

What kind of magazine are you using?

 

[tec9]

It is a 30 round Zmag that I bought new.

 

[tec9]

The safety switch feels tight and functions as far as I can tell.

 

[FAL]

Did you run the bolt over the empty mag several times? Sometimes the Zmags need a little shaved off the top of the mag before they run right. They're great mags, but every Mac is a bit different. I'd try that and then try it again.

Every Zmag I get, I run the bolt over the empty mag 10 times before I use it.

 

[Offmarksman]

I know you are frustrated and possibly concerned about your purchase. Rest assured that if it’s upper related, Richard will make it right. If it’s a part in the lower, many on the forum will get it figured out. And even if the lower is out of spec. Sam at Practical Solutions will get it fixed and running like a top. Just a thought, have you taken out the trip, and tried it. Doing this will make it full auto only. You could also try some snap caps and see what it does just hand cycling things...

 

[parrthed]

I had some rubbing of zmags on my M11/9. These guns do have their quirks. Just sanded a little of the paint off the top of the lips and it solved it.

 

[bruh44]

Where do you live? There's a lot of people on here with a lot if k knowledge about these guns. And many with M11s you could compare yours to.

 

[Jmacken37]

Where do you live? There's a lot of people on here with a lot if k knowledge about these guns. And many with M11s you could compare yours to.

Great advice. Hard to say without looking at what's going on. Virtual certainty that the problem lies with your vintage, sheet metal, crappy lower.

I'd check to make sure that your FCG is installed correctly...and replace the crappy stock parts with correct newer parts available from Lage Mfg

https://www.mac-11.info/fcg.htm

These are pretty basic guns but remember the Mac guns are full of shitty pot metal parts and had very loose tolerances.

 

[m11stuff@hotmail.com]

Check the sear spring and make sure it is not bent. Insert a small screw driver into the hole in the top of the sear and push it straight down and wiggle it. Also, make sure the safety is not being slid back to the safe position when cocking or firing. This can be caused by the sear spring being bent or your off hand bumping it. The bolt will wedge against the sear and lock the bolt back, causing a dead trigger and for the selector to not want to rotate.

Also, make sure the safety detente positively engages so the safety does not easily move between positions.

Definitely try your OEM upper too. If it has the same problem, the problem is in your lower.

 

[tec9]

UPDATE! As mentioned in my prior post, I was originally trying to sight in my red dot, so I just tried it on semi mode. When I got home last night, I tried cycling it by hand, using snap caps and it appeared to work fine in full auto mode. Tonight I took it to the range and tried it in full auto mode, and it worked! I have been emailing Richard Lage and he was able to offer a few suggestions. I am going to check/ replace my sear and spring when I get a chance. So it works in Full Auto- could be worse!

 

[m11stuff@hotmail.com]

Make sure your trigger spring is installed correctly. That could be affecting the semi-auto function.

 

[DistalRadius]

Somebody save this photo.



You are welcome!

 

[skoda]

Thanks Distal, that's nice.

Tec 9 - I highly recommend that you go to the Lage site and buy all of the internal fire control parts that they sell and replace your OEM parts. The quality of design, materials, and manufacture will pay for it a thousand times over in not messing with the OEM stuff.

 

[tec9]

When I ordered my Max31 upper, I added a few of the internal parts for my M11 to the order. After getting suggestions from Richard and from this group, it seemed the sear was in question. Luckily, this was one of the parts I ordered with the Max31, so I had one ready. After installing this, I took my M11 back to the range, and it seems to work fine now in semi auto mode, and full auto. (Semi mode is what would cause my gun to lock up) I didn’t get a whole lot a time to play with it, and won’t be able to get back at the range till next weekend....but it seems like that was the culprit!
The spring from the OEM sear was a little tough to pull out, and may not have been fully seated in the sear. The spring seems to fit smoother and sit deeper in the Lage sear.
Thanks for all the help!

 

[Garrett]

Interesting. I had forgotten that my MAX-31 doesn’t like to run in semi-auto. But I don’t recal the last time I tried running it that way, so it hasn’t really been an issue.

The MAX-11 and any OEM-style upper all seem to work fine in S/A though.