Problem with my M-11

[Born2Lose]

I finally finished the m-11 a few months ago using various sources for parts.
Now the only problem is I apparently built it as a single shot. Even worse than that i built it as a single shot that i must disassemble in between each shot!
Load up mag..cock it..pull the trigger..BANG..then charging handle can cock all the way to the rear instead of stopping halfway and the hammer gets stuck on the sear and won't come off until i pull gun apart. I thought it was due to some welding remnants but after relieving that and testing again it does the same thing!
I can't get it to stick unless i fire a live round. Hand cycling with snap caps cannot duplicate the problem.

PLEASE HELP!
I'll try to post pics tomorrow night.

[chiz]

Did you put the buffer on the back of the bolt assembly. And is the bolt still hitting the top of the feed ramp. One other thing to check is the width off the upper when it it not in the lower. Then measure the lower. since the gun is painted it might be a tight fit and when the gun is fired the bolt is sticking in the rear. I had to tweak one of mine because the bolt was sticking.

[Born2Lose]

Did you put the buffer on the back of the bolt assembly. And is the bolt still hitting the top of the feed ramp. One other thing to check is the width off the upper when it it not in the lower. Then measure the lower. since the gun is painted it might be a tight fit and when the gun is fired the bolt is sticking in the rear. I had to tweak one of mine because the bolt was sticking.

Yes the buffer is there. No the bolt is not hitting the feed ramp.
The lower is painted but only on the outside. I blued the inside.
The hammer gets caught when it engages the sear. Then when i pull the trigger it won't release the hammer until i remove the hammer bar from the frame. Pictures tonight might clarify.

[saki302]

Maybe you need to adjust the catch(es) on the hammer- you can test engagement with the upper off- just hold the trigger back, and cock the hammer by hand- it should release from the secondary catch when you release the trigger.

Assuming you built the MAC from a kit, the upper is usually pre-assembled and shouldn't have any issues.

-Dave

[Born2Lose]

Maybe you need to adjust the catch(es) on the hammer- you can test engagement with the upper off- just hold the trigger back, and cock the hammer by hand- it should release from the secondary catch when you release the trigger.

Assuming you built the MAC from a kit, the upper is usually pre-assembled and shouldn't have any issues.

-Dave

I cannot replicate the problem in any other way other than firing a live round.
Hand cycling doesn't do it with the upper on or off.

Upper is a complete i bought from an online vendor.

[USMG]

make sure you have the sear/trigger bar positioned correctly. its the little piece that sits just behind the trigger and rests against the front of the sear plate arms. If you have it in backwards the spacing will be off and you will have trouble releasing the hammer from the sear plate. The sear plate is that tuning fork looking piece, there is no sear on a semi. I have attached a photo and you can barely see the angle of it just in front of the trigger. The angled section sits against the trigger. I just added another photo with the trigger and other forward parts removed to see the trigger bar. Hope this helps.

[AJAX22]

It's easy to assemble the buffer invorrectly can you show us a pic? Of the bolt assembly, and of the assbles lower internals?

[chiz]

I looked at a picture that you sent me a while ago and the trigger bar was correct and nothing else looked bad.

[Born2Lose]

Yes trigger bar is correctly oriented.
What is the average pull distance of the trigger to release the hammer? My pull seems really short from resting position until it hits the flat part of the safety bar.
I'm starting to wonder if i need to shave a hair off the hammer hook or remove some of the flat part of the safety bar.
Here are some pictures. (Click to enlarge)

[USMG]

If you built it from parts then the side plates are probably not exact, most plates I have seen have been off. the hammer pin hole may be too close and that explains why it has trouble disconnecting from the sear plate. You may try shaving the hammer a bit as you suggested to get the correct distance. We sell a lot of the cobray hammers as they break and people try to file them down to make their guns runs full auto.

[chiz]

I re-read what you wrote and at first I thought that when you said the charging handle went all the way back that you meant the bolt was getting stuck. But I guess you mean just the hammer is stuck. It looks like the sear plate should sit back a little bit more so that when you pull the trigger it will release the hammer. Removing a little from the back of the trigger bar may work but only remove it from the center where it hits the feed ramp. Or like you said you may have to shave a little of of the hammer. Do it carefully though. If you take too much off it will run full auto.

[Born2Lose]

I re-read what you wrote and at first I thought that when you said the charging handle went all the way back that you meant the bolt was getting stuck. But I guess you mean just the hammer is stuck. It looks like the sear plate should sit back a little bit more so that when you pull the trigger it will release the hammer. Removing a little from the back of the trigger bar may work but only remove it from the center where it hits the feed ramp. Or like you said you may have to shave a little of of the hammer. Do it carefully though. If you take too much off it will run full auto.

Do you think that removing a bit of the flat part of the safety bar will work? If i'm thinking correctly it will allow the sear plate to push back farther thereby releasing the hammer all without the risk of a ten year stay in ClubFed.
I previously relieved a bit of the center of the trigger bar thinking it would solve the problem and it did not.
The bar doesn't even come close to resting against the base of the feed ramp with the trigger fully depressed. It hits flat part of the safety bar well before that.

[USMG]

if you removed part of the trigger bar then the sear plate would be closer to the front of the gun making it more difficult for the hammer to disengage. The trigger now has to push the sear plate back further and that wont happen. If anything, take off a bit of the sear plate where the hammer catches or trim the hammer just a bit. All of this is only an option if everything else in your gun is in spec. Since its a build up, its more likely that the pin holes are off. Everything should have been checked before assembly.

[Born2Lose]

No i removed some of the rear of the trigger bar and only in the center where it would meet the base of the feed ramp (If it actually could move that far).
I think you may be right about the holes being off but i think it is too high not too far front or back. Hence it hitting the flat area of the safety bar too soon as to not allow the trigger bar to push the sear plate far enough back to disengage the hammer from sear plate. *end run-on sentence*

[scotthmt]

I know your pain, it took me 3 diff rainge trips before i had my mac build functioning right, and damn do these things have horrid trigger slap.