Mg34 problems

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JasonGTA
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Mg34 problems

Post by JasonGTA »

*sorry for wall of text*

Tldr: bought tnw mg-34, action very tight and doesnt cylce when shot, it also doesnt feed properly. cam rivits all not flush, lots of burrs (I polish it all flush). C clamps buggered, 1 outside rollers inside diamter too big, cracked, flat spots on outside.

Hello everyone, this is my first day registered on this website and my first post. I live in Canada so the only option for me is a TNW Mg34. So I ended up buying one and I tried running it the first time the other day and it did not run as expected. The first thing I noticed ( befor shooting it and before researching it, which I have done tons over the last few days) is that pulling back the bolt was very, very difficult. I checked the cam rivits and that area and all 3 rivits were sticking up and there was a lot of burrs in the area, so I polished it all smooth.


That didnt work as well as I hoped so I checked the bolt rollers, both end rollers on both sides would fall off when I removed the bolt and I figured they were all like this, but once I researched it I found out the c clamps were not there, I later found them both wedged in the outside rollers ring. Neither of them work properly. But thats not all folks, on one of the outside rollers the inside diamater is too big, And the roller freely moves on it, it also has cracks on it and multiple flat spots on the outside diamater of it. I filed and polished all the spots round.


The bolt still fits tightly into the receiver ( only where the ejection port starts and an inch or so before the bolt head goes dissapears into the gun). But wait, theres more. The ejector rod was extremely long and was binding so I grinded it and timed it properly with the ejector plate. The plate is nice and tight, I guess thats the only thing not messed up in this gun haha. Ok so for feeding, this gun never feeds properly, it either pulls the belt with the round, turns the round on such an angle where it jams the whole system (while still in belt), pushed the bullet tip into the feed tray jamming the bullet into the case and jamming the gun, and if it ever does feed into the gun properly the bolt does not properly close fully and it does not eject the round, I found this out while feeding live ammo after attempting to fix it and one round being fed jammed into another round that was in the barrel already that didnt get grabbed by the bolt ( because the bolt does not close over the round fully) causing the primer of the round in the chamber to explode, thankfully the powder didnt light causing some bad things to happen.

Please can anyone help me figure how to fix this gun? I have already emailed TNW and I am waiting for the reply. Any tips or tricks to fix the problems would br lovely.

Thanks for reading this wall of text! I love the look of my mg34 and dont want to have to get rid of it!
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JBaum
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Re: Mg34 problems

Post by JBaum »

Wow, that's terrible. If you bought it from a dealer, I'd take it back and let them fix it. If you bought it from a private seller, you better have bought it cheap. Real cheap.

Everything you list is fixable, but before you start getting advice, wait to see what TNW says.

And welcome to the board. We have the knowledge to get your gun working, if you have the ability needed to do the work :)
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Re: Mg34 problems

Post by messerschmittfan »

I would return the bolt and ask Lance to fix roller issue - the rollers need to be the same size and have NO flat spots. TNW has new rollers. The ejection rod length seems to be a continuing problem, as well as the angle cut on the rod. I always check the rod and angle for the bolts when I get them back from them. I have several TNW semi-auto MG34's and they all run flawlessly now. You might want to swap out the firing pin spring for a full auto one to reduce the cocking resistance. It will not cause the gun to go full auto, just make it easier to cock. I was told that the heavy spring is to insure that the military primers are hit properly but have no problem with the two bolts that I had to put the original springs in. Keep in mind that it will take about 100 rounds through the gun to loosen it up to fire as it should. I soak my bolts in motor oil and drip dry and use them that way for the first 50 rounds. It makes a mess but allows the gun to fire a lot better. After a good cleaning and another 50 rounds they normally run great. Harry
JasonGTA
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Re: Mg34 problems

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Its harder for me to sent it to TnW because I am in Canada. I have the bolt sitting in motor oil now and will drain it and try it out soon. If any Canadian members have extra rollers I will take them off your hands for you. Also, when watching the gun shoot without the top cover on the bolt moves back in the receiver but just not far enough for ejection and to pick up another round. Could this problem be linked to the rollers being off? The recoil spring is also 20 1/2" long and very tight. Should I get a new one?
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Re: Mg34 problems

Post by JasonGTA »

Just tried shooting it after soaking the bolt and it still does not eject
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Re: Mg34 problems

Post by JBaum »

How long the spring is out of the gun is irrelevant to anything. What you need to check is that the coils of the spring aren't all touching each other before the bolt is fully rearward. That would stop the ejector from working as the bolt is unable to get far enough rearward for the pin to hit the plate. A loss of recoil power due to friction of the bolt (any part of it, including rollers) will cause the same problem.

Keep investigating and reporting here. You're making progress.
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Re: Mg34 problems

Post by anjongni »

The TNW bolt cocks on opening, using up a lot of the recoil energy just to overcome the very stiff firing-pin spring.
It is tough to cock the bolt by hand while holding it...imagine the bolt cocking against the friction of the sliding surfaces, rollers, and the recoil spring, all while operating the cartridge feed system too.
The Bolt head and tailpiece slide across each other against resistance of the spring. Super-lube helps at this interface.
You might replace the stiff TNW firing pin spring with the WW2 full-auto spring as Harry suggested. This worked for me. Runs well now.
If not for Tim and Walt in Vernona, Oregon getting the design approved, we wouldn't have ANY semi-auto MG34's. The Feds won't let that one sneak by again. It just needs the bugs worked out. We're all here to help you accomplish that.
Best of luck...Phil
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