The MG34 Repair and Troubleshooting Thread
- Thread starter DILLIGAF
- Start date
FirearmsEnthusiast
CGN frequent flyer
- Location
- Kingston, ON
Someone got a nice deal. Maybe they'll appear on this thread soon when they need to get their '34 up and running (or to fix it when it breaks!)...
stormwolf18
Regular
- Location
- Terrebonne
Pulled the charging handle and tried to dry fire but no click, what is wrong ?
Any sites with info with the common problems of tnw mg34 ?
Any sites with info with the common problems of tnw mg34 ?
FirearmsEnthusiast
CGN frequent flyer
- Location
- Kingston, ON
Sorry to hear that. This thread is turning into one of the better resources out there, and there are some posts on some US forums that also can help.
For your problem, I would suggest removing the bolt from the receiver, then twist and straighten it (as if you were reinstalling in the receiver). The bolt should then be cocked and stay that way, with the sear lever (at bottom of bolt, at end farthest away from the bolt face) engaging the sear ring.
Then push inward on the rearmost part of the sear lever (could take some pressure) - the firing pin should trip.
If it doesn’t, maybe the bolt isn’t remaining cocked (sear and ring problem). If it cocks and trips properly while outside the receiver. then I would remove the trigger group and look at the trigger bar and rollers...
Let us know how it goes...we’re here to help!
I agree with this comment.
- Location
- Leduc County, Alberta
Does anyone here have a couple of these for sale? I’ve got the super old style SA Sear that doesn’t have the little “shelf” on the sear assembly. Hence the new sear lever etc from Marstar won’t fit...
I tried Wolverine, and they have none and can’t get any, and TNW won’t respond to my emails. If anyone is able to get these parts outta the US, I can pay a finders fee too... just kinda stuck at the moment trying to update 2x bolts.
Cheers.
Attachments
Usually when that happens the bolt is not completely into battery
Check for binding in the bolt mechanism and the barrel extension where the bolt screws into. Make sure the bolt rollers are good and not wore out or falling apart. Grease up everything really good too, reciever channel, bolt rollers, barrel extension threads, barrel return plunger, back part of the bolt where the sear assembly slides and don't forget the barrel bushings in the front shroud and trigger rollers/ sear assembly
A good grease to use is super lube. You can get it at greggs distributing
Try an original German firing pin spring instead of the heavy duty tnw one as that causes problems too
This thread has lots of good information, any questions just ask there's a few guys on here who are knowledgeable on the tnw 34
FirearmsEnthusiast
CGN frequent flyer
- Location
- Kingston, ON
Agree that this could also be a cause...also make sure that you are not riding the charging handle when cycling the gun - let it fly forward to ensure the bolt goes fully into battery. This, along with checking the sear engagement with the bolt out of the receiver as I described before would be good initial cause checks...
- Location
- Leduc County, Alberta
I have the new Marstar parts. They don’t fit the old style of sear ring. The picture I posted was of the new style sear and sear ring assembly. The old style doesn’t have the shelf which changes the fulcrum point of the sear lever and makes the trigger pull lighter.
- Location
- Leduc County, Alberta
Probably because the parts Marstar sells are cheap and easy enough to manufacture, unlike the sear ring assembly itself which is much more complicated? Not really sure.
stormwolf18
Regular
- Location
- Terrebonne
ok, it was indeed out of battery, something was stuck between the barrel and the receiver. I'm glad nothing was broken, i'm new to this firearm and it looks kinda hard to fix.
Took my gun to the range and now have a new problem.
After firing a round, the bolt locks back in the rear of the receiver more often than not.
This happened with both the TNW FP spring and an original FP spring.
Pulling the cocking handle back releases the bolt, and it drives forward.
I'm not sure what's causing the bolt to lock back. I'll have to investigate further.
My booster cone is drilled .450 and had the flashhider snugged up. Maybe too snug?
I have about 90ish rounds through the gun. Maybe try some different ammo?
Opinions?
TIA
After firing a round, the bolt locks back in the rear of the receiver more often than not.
This happened with both the TNW FP spring and an original FP spring.
Pulling the cocking handle back releases the bolt, and it drives forward.
I'm not sure what's causing the bolt to lock back. I'll have to investigate further.
My booster cone is drilled .450 and had the flashhider snugged up. Maybe too snug?
I have about 90ish rounds through the gun. Maybe try some different ammo?
Opinions?
TIA
Last edited:
this thread has completely turned into a repair thread now. Too bad TNW is such a sh!ty company.
1340. the bolt has to glide like butter in the receiver, so check your bolt wheels and the receiver for imperfections like rough spots or a tight fit for the wheels to squeeze through your receiver.
It could also, and most likely, be your ejector binding on your ejector plate. Check where the bolt is being stopped and try to determine where the ejector pin could be at that point. If your ejector plate has any wear on the ramp, it should be replaced.
lets get all these MG34's running! yes, its a labor of love, don't give up.
1340. the bolt has to glide like butter in the receiver, so check your bolt wheels and the receiver for imperfections like rough spots or a tight fit for the wheels to squeeze through your receiver.
It could also, and most likely, be your ejector binding on your ejector plate. Check where the bolt is being stopped and try to determine where the ejector pin could be at that point. If your ejector plate has any wear on the ramp, it should be replaced.
lets get all these MG34's running! yes, its a labor of love, don't give up.
FirearmsEnthusiast
CGN frequent flyer
- Location
- Kingston, ON
Idea - pull the bolt back all the way with the charging handle. Then engage the safety with the bolt held back, and ease the bolt forward until it is held by the safety. Note the position of the bolt - it will be partway back. Is this the same position that the bolt ends up in when it locks back in the receiver during firing? If so, the safety may be partially engaging when the gun is in recoil. A bit of a longshot.
Other potential causes (as noted by other posters):
- bolt is getting snagged in the receiver - check for debris and ensure the bolt tail surfaces where it contacts the receiver are lubricated with TW25B or white grease.
- ejector pin is protruding out from the bolt body enough for it to get snagged in the receiver - either near the back (like when you try to install the bolt with the ejector pin not fully forward) or snagging on the ejector plate
As was stated check the bolt rollers to make sure they are good and not sloppy, one of mine got so sloppy that the circlip in the bolt wouldn't hold it in and caused it to jam in the reciever.
Check the ejector and ejector plate it may be binding. If you can remove the ejector put the bolt back in the gun and manually cycle the bolt with the charging handle to see if the bolt body snags or drags on the ejector plate. I had this problem too
One more thing to try is to remove the spacer tnw put on the end of the recoil spring. Sometimes the main spring can bind up
Check the ejector and ejector plate it may be binding. If you can remove the ejector put the bolt back in the gun and manually cycle the bolt with the charging handle to see if the bolt body snags or drags on the ejector plate. I had this problem too
One more thing to try is to remove the spacer tnw put on the end of the recoil spring. Sometimes the main spring can bind up
