www.MG42.us

Hello all,
I finally had a chance to shoot the TNW 34, and had a few small issues with feed and extraction. I read alot of the old posts, and I think i have a few areas identified that i need to look at. My question is, since TNW does NOT supply a descent manual for their weapon, does anybody out there know how to disassemble the bolt for cleaning? It doesnt seem to follow the normal bolt procedure for the FA model.

I also had a few ejection problems with the gun, shooting romanian surplus, which i have heard feeds/shoots well in other guys guns. My ejector rod/pin seems to have some hits to the end, and is a bit malformed. Is this normal? Also, i did notice that both ejector plate screws were high, as in protruding above the surface slightly, despite being tightened up fully. The front screw even has a wear/rub pattern setting up, with the inner 1/3 sruface of the screw head being worn down. Now, i realize this is not normal, and needs attention, but could this be also causing feed/ejection problems?

By ejectin problems, i mean the round is being fed, but the spent casing gets caught up/jammed in the ejection port. Most times it seems as if the open end of the spent casing is facing aft (toward the shooter) and inside the left rail channel. There were times where it also stayed central in the port, with the new round getting jammed near the chamber by the spent round

TNW seems to say that lube is critical. They even sell this special grease. Does the MG34 series gun require ALOT of grease on the camming sections, including originals? I cleaned and oiled it well, and put a few small dots of grease in those areas, but didnt load it up. So, rub your lamps, and let the genies fly, as i appreciate all your commnets and help in getting this thing runing well.

FYI, i put 4 belts thru it (same belt), the first belt had a lot of issues, feed, and ejection wise. 2nd belt much better (only 2 feed issues), 3rd soso, and the 4th pretty much went thru OK. Would this be a lube issues, or just the gun warming up?

Again, thanks for the help in advance,
K.J.

I'm pressed for time, so forgive me if I'm a bit brief. I don't have the TNW bolt in front of me, or the time to write a dis-assembly procedure. It is similar to the F/A bolt tear down. I don't know where you got stuck so I can't really help. I think the best choise for a manual and also a complete overview of the '34 is the Collector Grade Publication's book on the MG34 and MG 42. The '34 is "belt sensitive". You don't say what kind of belt you have. For flawless feeding the belts cannot be too tight. The failures to eject sound like short recoil. I use the LSA oil and plenty of it. Critical to extraction is a very clean chamber and clean ammo. Drity cases can screw up everything quickly. Also, to prevent distruction of the cams amd bolt rollers, you must lube the barrel locking threads. This friction, when unlocking the bolt from the barrel, if unchecked by lubrication, will put enormouse stress on the cams and rollers and wear those parts out quickly.. I have the "gun needs to warm up" thing going on too. Takes about 75 rounds to really get going, less if I do a real carefull lube when assembling after cleaning. The peaning is common on the ejector pin. They wear out. Lastly, your feed arm probably is hitting the ejector block screw and you should file it flush. Good luck!

FWIW, my ejector screws were definitely contacting the feed arm slightly. The front screw was peening a little on the leading edge, they were proud maybe 1mm. It wasn't damaging the feed arm, but there was a bright spot on it where it was rubbing. I suspect the arm is harder steel than the screw.

When cycling the action you could *just* feel it hanging slighly as the arm passed over and rubbed the crew. 5 minutes of carefully filing the screw heads eliminated the contact completely. Seems to cycle smoother by hand now. In my case though, it wasn't affecting function during live fire.

So far my TNW "fixes" have included those offending screws and boring the cooster cone from 9.25mm to 10.9mm. It's too bad that $400 buys you a gun that still needs fiddling and tinkering, but there's not much else out there for options unless you are a fantastic welder

you still didn't tell me about the belts. To cut to the chase, rounds must be easy to push in. If you really have to shove them in, you will get miss feeds. The only TNW receiver I worked on had jams where the round hit the revceiver and stopped the bolt cold by having the bullet point hit right at the edge of the ramp that pushes the round down toward the chamber. If it makes you feel any better, my all matching, all original gun needed just as much work to fix, and it was $5500.
For the ejection problems, it sounds like short recoil. Did lubing the barrel extention threads help? Third and fourth belts running OK is consistant with my experiance.

Which barrel extension threads? Do you mean the interrupted threads the bolt head locks into? If so, my TNW came with those heavily slathered in white (lithium?) grease from the factory.

I appreciate the help!! This is an update on what i had installed on the gun while shooting:
1. 11 MM booster cone.
2. 5/38 dated belt, packed in cosmoline when i got it. I assume it was a new belt, as i didnt see much wear, and now that you mention it, it did seem a bit stiff. I used/reloaded that same belt for all the firing.
3. Started with a clean gun, lubed, but no grease, except a very small amout on the bolt.
4. Shot the romanian 153g ammo. Would this make a difference in booster cone selection? Affect recoil?

sorry for the delay i responding. In response to the bolt disassembly, that sear in the center has me puzzled on how to properly service it.

Thanks,
Kris

These pigs run best when greased. Heavily greased. Try that next. Also, cosmo on the belt will make it work poorly. Make sure the belt is clean and not too tight on the rounds.

The 11mm cone is the right one. Don't change that.

The rounds aren't ejecting likely because the bolt is short-stroking such that the ejector isn't hitting the ejection plate to fire the spent rounds out the bottom of the receiver.

The originals weren't greased, they were originally oiled on all friction surfaces, but they had unlimited spare parts to work with. Grease isn't as friendly in the field when you introduce dust, sand, grit, etc. but for range work it will prolong the service life of your gun's wearing parts and help reduce bolt friction.

You could likely make it work reliably by putting the 9.25mm cone back in, but then it will be recoiling harder than it should be. Better to make it work with specification parts than to take the easy fix and beat up your cams prematurely IMHO.

I had the same issue. Changed the ejector pin with a new one from TNW. Problem gone.