New to the Forum, Problems with my MG34

[42rocker]

With sarco talk to Dave on machine gun stuff as he knows those parts. email him and he normally phones you back (if requested).

Or thank to Brian at brp

http://www.brpguns.com/

or check with these folks

http://mg34.com/

Good Luck

Later 42rocker

[anjongni]

Hi Mggunner, I'm certainly no f/a expert, but is it possible that perhaps at one time your parts kit was used for .308? If the booster cone oriface were of the reduced size used for .308, it might be too restricted for use with 8mm. It would be hard on the primers, and the gun in general. Might be worth measuring it. Good luck!...Phil

[Mudsharkangler]

Good discussion here. Thanks.

[TactAdv]

If the booster cone oriface were of the reduced size used for .308, it might be too restricted for use with 8mm. It would be hard on the primers........

....actually, I think you'd not find a correlation there. ;-)

Irregardless of the booster orifice size installed, "correct" for the cartridge propellant charge or not, the problem of primer set back is one of another color entirely. This is because the booster nozzle only imparts its' force well AFTER the high-pressure gas efflux has exited the barrel bore, venting to atmosphere.

Primer set back occurs as a direct result of the high pressure gasses, when still constricted by a "closed bore" situation before the projectile has un-corked, attempting to vent through the path of least resistance. Remember that the primer is contained in the web of the cartridge case by the same forces that keep the case walls obturated against the chamber walls of the barrel, yet at a MUCH lower effective adhesion. If the back of the cartridge case is left un-supported even incrementally (like, from partial bolt unlocking here), the primer obturation is the weakest link and becomes the path of least resistance in the whole high-pressure event......the primer will stop moving back either when it reaches support again in the form of the bolt face, or when the bullet un-corks dropping the contained pressures instantaneously to zero(ambient atmospheric).

The booster nozzle only reacts to the force of the effluxing gases well after bore pressures have dropped to ambient/zero. So, no, the booster nozzle orifice has no effect on primer set back.

-TomH

[dwmmg08]

Wow, Excellent Reply TomH!!! I learned something just from reading your post. I'll go check mine. I haven't had many problems with primers blowing out, but we replaced so much stuff repairing my MG34 that I can't tell you if we did that or not right now.

I can add to this that the Yugo ammo I've shot is actually pretty in tune with my MG34, as a huge amount of the parts in my MG34 came from Yugoslavian rebuilt guns because they were some of the last users of the MG34 on a grand scale. I was joking with a friend the other day that I should talk to it in Croatian or Serbian to make it work, maybe not German! LOL!

The Yugo ammo I have is from the 1950's; the MG34 was a standard arm of the Yugo's then, so this ammo was actually made to run in an MG34. It works really really well in my gun, better even than the Romanian, which is much better in my Maxims. Neither of those choices are poor for shooting.

Now I have shot some crap I will never shoot again in my MG's a long time ago (Italian 1950's surplus from Paragon...) but I'm a lot pickier now. The Romanian stuff is top notch. The Yugo stuff is very very good, and should run really well in your MG34.

[anjongni]

It's always interesting to learn from the fellows here, many years of experience out there. I had to get an old junk barrel jacket to check it out - I thought the bolt latch was just there to hold the cocking handle from rattling! I don't think I've ever seen one for sale separately. One of the original questions was about firing pin protrusion, so I grabbed a couple bolts off of the shelf. The MG34 is most, at over .100". Seems like a lot. This bolt might be worn out. The AR10 is new, much less protrusion. The Thompson M1a1 just has a tiny bump, but it's also new. Tom, why the lack of consensus on how "deeply" to penetrate the primer? Phil

[jackxxx]

I wonder if the muzzle cone may have something to do with it.. I reload for my f/a mg34 and i do not cramp the primers at all and never had one to blow out.. The fact that you are shooting miltary surplus ammo and having primers that have a heavy crimp blow out something is bad wrong... I would check the muzzle cone and make sure it is large enough. I think it is suppose be 11 mm or 13mm have to ask the other guys to be sure..

[TactAdv]

I wonder if the muzzle cone may have something to do with it..

(Hint) Look two posts above. ;-) ;-)

[jackxxx]

I wonder if the muzzle cone may have something to do with it..

(Hint) Look two posts above. ;-) ;-)

I know.. Saw it just as soon as i posted a reply.. Now that is what happens when you read a forum and post replys while driving..hehehe

[42rocker]

As long as you did not score to many points while driving.....

Later 42rocker

[mggunner34]

so I've located the bolt stop from a couple of different sources, seems sarco thinks its a charging handle part (i guess half right) and they sell the "kit" (bolt stop and spring) for about $25, I also located them in Germany itself for 28.58 (after currency conversion).

here's the funny thing,
I contacted by email a few individuals about this part also, I wont name who this is but he wanted $100 for new ones and $75 for used ones before shipping and without the spring!!

now if this isn't price gouging I don't know what is, just because I have a very expensive firearm doesn't mean I'm an idiot and I'll pay anything for a $25 part. I'd rather buy a whole new barrel jacket than spend that much on one (albeit) important part.

Do you guys see this kind of ridiculous markup often with MG34 parts??

[anjongni]

You have to be careful with Sarco's descriptions. I believe that the part that they offer is the charging handle "catch" and the "spring-steel" part that is riveted together to form the charging handle. I've never seen the bolt catch available separately. If anyone on GB has it, it would be "yazooka" from Europe or "mg34gunner" in CA. They each have a lot of expensive parts... Phil

[mggunner34]

I've seen them by themselves at the SAR show here in phoenix, I cant remember which vendor had them. but either way $100 for a bolt stop is crazy when i can get a whole barrel jacket for 4-500. why would sarco sell charging handles for so cheap if its not the correct part? a CH is definately more than $25 even if its not assembled with the "catch" part of it

[TactAdv]

A couple of points I'd toss out-

1. This part is almost never found "loose", by itself, and as it is almost always encountered as an assembled part of the entire barrel-jacket master assembly, it is not commonly available separately here. This is one of those parts where HAVING one at hand is probably not worth spending too much energy worrying about what you paid for it. It is NOT a part that you'd want to have made, trust me. There are some interesting angularities to it and it enjoys some pretty high grade metallurgy and heat treatments. And finding a GOOD one can be a crap-shoot, as many of the available loose ones are "loose" because they were removed due to excess wear or other defect from troubled guns......like yours. Finding a good condition, serviceable one may cost you having to go buy a couple or more to find one decent one. It was NOT a part that was routinely replaced unless it was damaged or worn out, which was usually after a LONG service life of the gun, so the Germans did NOT place it as a high-wear or replace item and it was not made as a Tier I spare part, like say, extractors. Again, HAVING one when you NEED one beats not having one and keeping an extra $50.00 in your pocket.

2. If spending a $100.00 puts your $30K+/- gun back in operation, that's cheap in my book. It's all a matter of perspective; Nothing about these guns is cheap. You want some REAL fun, try finding an impossible to find critical part for an MG-81, MG-FFM, MG-131, MK-108, MG-151, etc., THEN you'll begin to appreciate what a lot of us "crazy" collectors go through to find "over-priced" parts!! ;-)

Pay the freight, get the part, go shooting.
-TomH

[mggunner34]

I do agree on the points you made and I know that the price of this part is insignificant compared to the value of the receiver (as mine is not matched) but really $100 for this one part? It just feels like getting ripped off especially when compared to the individual price of all the small parts I can think of and lookup online, even ones that (i wouldnt think) have a high replacement rate (top cover pins, bipod studs, bolt carriers). It would seem that compared to the mg81s and other awesome german wwII machineguns MG34 parts are relatively plentiful.

[mggunner34]

I also found these individually on Marstar I've never ordered anything from them before, have any of you? Will they even sell to me since I'm in the US and this is an MG part?

[anjongni]

Numrich and Sarco's "bolt catch and spring kit" consists of the parts shown in the photo, riveted to the c/h. Original, complete charge handles are expensive.
Marstar has the part, m34-020. "Just fill out a form 6", they have told me. You could try this...or, I'll be glad to swap you the catch from the shroud shown in the photo a few posts up. Looks good to me, and I won't ever be shooting it. Or you could try the complete shroud. It's good, except someone took after it with a grinder to fit it on the wrong lafette. Any tricks to removal of the catch? Phil

[mggunner34]

you just knock out the pin holding the catch in place and watch out for the spring, send me an im and let me know what you'd want for your serviceable bolt stop