MG34 Nightmare of issues's, easy fix?!?!

[anjongni]

Hi cbass, I believe that TNW owns the "approval", i.e. that type of legal semi-auto bolt modification. Stan's PG receivers are of course custom made frome cut-up ones and might vary from one to another. They use the TNW approval. The bolt parts are made by Tim and Walt in Vernona, OR. Did you purchase it new, or assemble it? If you're the first one to combine this bolt and receiver, check the ejector pin operation. It should slide smoothly past. The pin takes a little bevel in there where the pin drags across the plate. And yes, practice the loading sequence. Best of luck....Phil

[cbass]

@ anjongni

I got this off Gunbroker, from a gun shop out in Arizona. He had Project Arms build a few kits for his shop but he never fired the mg34. Which is beleivable, because it was drowned in cosmoline (took me 10 hrs to get it out and the house still smells of cosmoline ) I cheked the bolt last night to see how it slides and if i come across and tight spots and it was smooth as a baby's bottom. How long are original recoil springs, because my friend says he cut his to 14 inches and mine doesnt fit in with ease. Its a small struggle.

[cbass]

@ ajongni


I just did the proper loading technic with a few dummy rounds, and I had 110% proper feed and ejections and most importnantly the bolt went forward everytime

Now all I gotta do is take it friday morning to the range and hope for the same results

Rupp

[42rocker]

Good Luck

Later 42rocker

[ChrisPCook]

I agree with the checking the ejector pin, I have bolts that have slide easy and some that don't, and some of that is dependent upon the ejector pin sliding easily, but still working properly under the ejector plate. I'd also suggest taking a sharp pointed tool (awl, scribe, etc.) and run it through the inside of the receiver where it has been rewelded, see if it "snags" anywhere. If it does smooth that are out (I've used dremel tools with a large cutoff wheel to reach under and smooth and area, have been able to knock some down with a file from one end or the other, and sometimes have used a 100 or 80 grit sandpaper on the finger to reach in and smooth out an area), it all takes time, but the tight tolerances can easily snag up a bolt. Chris...

[cbass]

@ chrispcook

Im going to test fire it out on friday, and ket you guys know the result.

Rupp

[flemgunner]

Sorry Im late the the party but my inet went down at home. Anywho glad you got some help on this these guys rock for info

[cbass]

Hey guys,

I just got back from the range and we made some progress BUT there is a different issue now.

Well what progress my mg has made, is that the bolt does go all the way forward every time now and its not getting stuck anymore

Now here are the issue's

1) the bolt did not go back far enough to eject and chamber the next round. It would go back just enough that you would think it cycled, so your able to pull the trigger but nothing happens, because the fired casing is still in there. SO all in all, not getting the bolt to cylce.

2) this has happened alot today. The bolt would go all the way forward and lock, and I would get weak primer strikes. And I could also pull the trigger and the firing pin already fired when the bolt went forward.

3) a few rounds (approx 3) the bullet came out of the casing when the bolt went forward or ejected unsure. Then I had a few rounds were the bullet slightly came out of the casing aswell.

In the picture from left to right the first round did not strike but the bullet came apart from the casing while either being chambered or ejecting. The middle round was a lite primer strike, but same as the previous round the bullet was seperated from the casing. and the the right round was that the bullet was loose from the casing but it wasnt fired so im assuming that the issues are happening during the chambering phase.

cbass

[cbass]

here are the pics if the y wont allow you to download and view them

[anjongni]

mg34%20fp%20spring%20004.jpg (16.93 KiB) Viewed 2168 times

Hi cbass, eventually you'll have to check out your firing pin & spring. Pieces of primer and carbon get inside the bolt head and can clog things up. Determine which spring you have too. One served the Wehrmacht well for many years, and the other, from TNW, is from a '65 Chevy 1/2 ton. You might try the German one. If you have the stiff spring, other issues arise. Since the semi-34 cocks on opening, it's a lot harder for the recoil forces to "unscrew" the bolt, introducing a lot of unnecessary friction. Since the firing pin arm is almost completely shrouded until the bolt has threaded all the way into the barrel, it shouldn't be able to fire out of battery. Not sure that the monster spring is needed. Also, it might be a good idea to try new, commercial ammo until you get things operating correctly, then go to the iffy older internet/gunshow stuff that might be part of the problem. Just my ideas. Be careful....Phil

[cbass]

Phil,

Im going to try some different ammo here within the next few weeks. For some reason I am unable to get to the firing pin and this is as far as i am able to take the bolt apart. I cant seem to get it to unlatch to were I can get th spring and firing pin out. Is there any easy method?

[anjongni]

cbass, It looks to me that you need to remove the firing pin retainer sleeve from the bolt head if you haven't already. Invert the bolt carrier, and use it to depress and rotate the sleeve to un-cam the pins. There is a very stiff spring in there working against you. Be careful. Once the sleeve is off, the f/p and spring will fall out. Do you have this TNW diagramme? Good luck....Phil

[cbass]

@ phil

For some reason no matter how much I try to depress and rotate the sleeve to un-cam the pins, I cannot get it to actually work. There is no movement no nothing in there, which is frustrating becasue I know there is alot of gunk in there that needs to be cleaned out. Is there any possible other ways to get it out?

cbass

[flemgunner]

Try putting the bolthead on a flat surface and use a deep socket to compress the sleeve. Then (after having taped the jaws) use some needle nose pliers to turn it

[anjongni]

cbass, I'll bet that the bolt is really hard to cock by hand..imagine what the gun goes through upon recoil! As seen in the drawing, the problem arrises because the semi-auto mod mills the two "removal slots" off of the f/p sleeve, leaving nothing to turn it by. The inverted bolt carrier trick doesn't help much. The heavy spring adds to the misery. I wasn't kidding about the hydraulic press earlier...take it to the shop and apply just enough pressure to compess the sleeve, using a socket, as Flem suggested, then turn it with pliers. It's really that tight.
You'll notice that Brian at BRP avoided all this sturm & drang by creating the XMG, using an AR lower to build a hammer-fired MG34 that seems to work very well. Good luck again...Phil

[cbass]

This wasnt as hard as I made it out to be, but I Finally got the entire bolt apart using the pieces of the bolt Here is a pic of it right after I pulled it out and you can see how filthy it was, with all the carbon on it. Cleaned it, and did a functions check, the click of the firing pin is alot louder so thats good.

Also I noticed alot of people using Romanian ammo especially in this video....notice who's shooting?

http://www.youtube.com/watch?v=SvZz1fH8B04

So I just got me a small batch of romanian that im gonna try on this weekend. Hopefully it'll work.

[cbass]

I just ordered some new parts for my 34. I was told that It could be the spring, because like I mentioed earlier the spring doesnt go in smooth. The spring is so long I have to force it into the receiver to make all of it fit. So im gonna try out the new spring and if that doesnt work, ill start cutting down the spring one inch at a time and try that.

regards,

Rupp

[cbass]

Fellows,

Sorry on that long delay to get back. Well after i finally ordered 1100 rnds of romanian 8mm I just found out that
no gun range in northern Virginia allows you to fire steel core ammunition. So im left with yugo ammo back from the 50's.

So i went out to the NRA range today and was able to only put 50rnds thru it but t about the last 15 rounds it finally managed to cycle itself which shocked me. So I drove hone and grabbed another 200 rnds went to a closer range amd amazing it was it was almost near perferct i fired 200 rnds and onky had to manually cycle about 10-20 times at moat not bad from having to do it after every round. I also realizes that theae jave to be running very wet i was using regular army clp. What lube is best, i was told miltec is good for an mg any one know? Also i.managed to take a little video ill jave that posted here later tonight/tomorrow.


Regards,

Cbass

[cbass]

After 150 rnds threw it was a bit dry but better then before.