Blank-Adapting the MG34.

Anything MG34 related.
Blanksguy
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Re: Blank-Adapting the MG34.

Post by Blanksguy »

I had one guy that ordered a 2-pcs. Blank-Barrel-Assembly in 7.62x51mm/.308 cal. tell me that he was having problems with .308 Blanks "chambering" fully.

I went ahead and ordered new chamber-reamers (both 8x57mm and .308 cal.)....and then ordered different "surplus" Blanks.

What I found out was that (again) not all "surplus" .308 Blanks are loaded the same....."AND" that not all .308 "surplus" Blanks are even made the same.
When checked against the SAAMI Spec. Books that has not only cartridges-specs. ....but also manufacturing-spec. for "chambers"....I found that some "surplus" Blanks are slightly too larger in OD (Outside-Diameter) as the photos below show.

What does this mean (?).........??????
What hapens is that the larger diameter POF Blanks start into the chamber and slow down as the bulleted-shape-crimp starts to jam into that smaller area (forcing-cone) in front of the chamber......this basically will jam and stop an MG34/SA34 from running.....and some MG42/SA42s.
Well, to insure that your MG34/SA34 (which does have a slightly longer "lock-up" time than the MG42) you may have to slightly alter the area infront of the chamber (called the "lead") which is a transition-area between the chamber to where the rifling (land & grooves) starts. (A 5/16" drill at .3125" should do the trick......"but" you may not want to use that same barrel-assembly for anything but "Blanks".

The MG34/SA34 also needs to use the larger "L" shaped Feed-Tray-Spacer to help guide the Blanks down into the chamber "and" not allow them to raise up at the front and jam against the top-front of the feed-tray cut-out.

Regards, RichardS in MI.
Blanksguy2001@chartermi.net
PS: Maybe someone can post photos and measurements for the plastic-Blanks.....which will run better "if" you use a 2-pcs. Blank-Barrel-Assembly. It has less weight just trying to move that short rear-section/piston.
.....and I will be making more of these 2-pcs. Blank-Barrel-Assemblies up in .308 cal shortly.....e-mail me if interested.
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Chuckm
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Re: Blank-Adapting the MG34.

Post by Chuckm »

This is a big THANK YOU to Richard for his 2-piece blank barrel for my MG42. I looks VERY nice and came well packed.

:bnija:

I will pick up another Barrel Carrier at Phoenix in December and be all set ! ! ! !

Again thanks Richard.

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Blanksguy
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Re: Blank-Adapting the MG34.

Post by Blanksguy »

Photo of the "L" shaped feed-tray spacer for firing shorter blanks in the MG34/SA34........such as the 7.62x51mm/.308 cal. surplus on the market now.

Notice how the front of the spacer's "tunnel" keeps the Blank from raising up at the front and hitting/stopping against the front-top of the cut-out on the feed-tray.

We are making a short run of these....and interested reenactors can contact me at my e-mail address for more information.

Regards, RichardS in MI.
Blanksguy2001@chartermi.net
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Re: Blank-Adapting the MG34.

Post by waffenmg34 »

Hello all & Richard,

I have had a bit of experience with my MG-34 semi-Auto and blank adapting and this thread has been very helpful troubleshooting issues with adapting the MG-34 for blanks and reenacting use.Since 2004 I have fired over 55,000 blanks through my MG-34 and probably helped pay for Joe Swanson's business overhead as well.
I've noticed a few things that are very important if you start out with a new MG-34 semi-auto from TNW. First off, break the gun in with live rounds prior to blank adaption. This wears in the bearing surfaces and action of the weapon and loosens things up a bit as the MG-34 is known for having tight tolerances. I put over 1,000 rounds of live 8mm through mine before adapting. Compared to some associates who did not, my gun behaves totally different to this day vs. my friend's MG-34's that only were broken in using blanks. (?) Something to note I guess. Also, clean and lubricate the gun as you break it in. No different I guess from changing the oil in your car frequently as you break in a new engine. It also allows you to get to know your MG-34 inside and out. Adapting, I used a cheap booster cone adapter with a live barrel, it was hit or miss at first, yet once I found the right aperture it was pretty reliable. A question: I recently found my two-piece blank firing barrel for my MG-34, I know from this thread that I will not be using a restricted booster cone. What I wonder, is do I need to restrict the forward portion of the barrel? If yes, how should I go about doing that? As I don't like threading the end of the barrel as adapter screws (restrictor plugs) work loose with gas pressure coming from behind and can pose a sizable hazard if they shoot out the barrel at reenactors. My thoughts are to tap and restrict it from the back end of the forward section of the barrel. Is this correct?

Chris Sharp
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Re: Blank-Adapting the MG34.

Post by Blanksguy »

Hi Chris,
Thank you for the posting.

On your 2-pcs. Blank-Firing-Barrel-Assembly for your MG34/SA34........you will need to drill and tap the muzzle for an allen-set-screw. Trying to Drill/Tap the opposite end will give you too much over-pressure due to the small area left for the blank to expand its pressure.
The use of a "Tap" allows for a partially-treaded (where the threads are shallow) area for the allen-set-screw to "lock" onto.
We have used these for years and I have never heard of any working loose during a reenactment......we (and other reenactors use this same type/style of Blank-Adapting for the 1911-series pistols....the M1-series Thompson SMG....the M3/M3A1 GreaseGun.......Stens........etc., etc..

Remember to start large on the BFA Hole-Size and wirk down in smaller sizes by .010" at a time.
.....and that not all Blanks are loaded to the same pressure so never mix Blanks on the same belt.

Regards, RichardS in MI.
US Army, Retired
Blanksguy2001@chartermi.net
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Re: Blank-Adapting the MG34.

Post by Avenger28 »

I’m trying to get my SA TNW 34 to run the plastic 308 blanks. I have all the 308 conversion parts. I was wondering if the 8mm two piece barrel would run the 308 blanks or if I would need to to a custom 2 piece 308 two piece?
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Re: Blank-Adapting the MG34.

Post by dogman5 »

After a couple of years of trying different things, I was finally able to get my SA34 running green plastics pretty reliably. I had to get a Norwegian top cover to feed them properly and use a 308 2 piece blank barrel that was made by Kriegsende MIlitaria (long since out of stock I believe). I had little success with the BRP 308 pawl and have found that the 308 feed tray spacer isn't needed at all. I'd be happy to answer any other questions you might have about this Avenger.
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Re: Blank-Adapting the MG34.

Post by Avenger28 »

Thanks for the reply dogman. I too have a Norwegian post war 308 top cover. I’m on the hunt for a two piece 308 blank barrel…. That seems to be the missing link
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Re: Blank-Adapting the MG34.

Post by dogman5 »

Yes, that's the main missing link at the moment. I was able to snag one up when they were available, but I don't see them out there very much. Have another friend looking for one too.
Blanksguy
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Re: Blank-Adapting the MG34.

Post by Blanksguy »

Why don't you go in together and have a local machinist make two of these (?).

Parts that you will need if you do this (to keep costs down in making one set) would be:
1: One shot-out or worn barrel to use for the front section .....and:
2: The Barrel-Extension so that when your machinist makes the rear-section/piston he can mate the two......and then do "Headspace" in 7.62x51mm NATO.
3: The Machinist will also require a good MG34 Bolt-Assembly and a 7.62x51mm NATO Chamber Reamer.

Because the German Plastic-Blank in 7.62x51mm NATO are so weak......the front section of the two-pcs, Blank Barrel-Assembly need to stay forward with the restriction in the muzzle of that section. But this has all been explained earlier.

Regards,
RichardS
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Re: Blank-Adapting the MG34.

Post by Avenger28 »

Blanksguy,

I was able to locate a two piece blank firing .308 mg34 barrel. Just to confirm installation no booster is used correct. The barrel it’s self has threaded restrictor screws in in.
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Re: Blank-Adapting the MG34.

Post by Blanksguy »

If your MG34 2-pcs. Blank-Barrel-Assm. was made correctly........you will not need a Booster.......just the flash-hider. the way that we made these was so the front (longer-section) would be held in place by the flair at the rear of that front-section.......with the screwed-in restrictor (Allen-set-screw drilled to different restrictions) making the operating pressure to push the Blank-Barrel-Assm. Rear-Section (the Piston and barrel-extension to the rear during firing of the Blanks to operate the system.

Any feeding issues are usually corrected by the use of a well-made adaptor fastened to the feed-tray.......as it needs to guide the blanks from the belt into the chamber. I gave Robb-Walters over at Atlantic-Wall-Blanks the design for a good MG34 feed-tray-adaptor.....he should still be making these. Tell him I referred you to him.

Last would be the use of 7.62x51mm feed-belts for less friction during feeding.

Regards, RichardS
US Army, RET
Blanksguy2001@outlook.com
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Re: Blank-Adapting the MG34.

Post by Avenger28 »

Richard,

Thanks for the reply and assistance on a thread from 2009. I have the brp 308 feed tray with the adapter that set screws in. I remember seeing some time ago a feed tray with a concave piece on attend to the upper portion of the feed tray. This would appear to stop the rounds from being forced “up” and causing failures to feed. Is this what you are referencing from Atlantic wall?

Thanks again,
Liam
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Re: Blank-Adapting the MG34.

Post by Blanksguy »

Correct.....when firing the shorter 7.62x51mm Blanks, they tend to raise up at the front when the bolt pushes them from the belt.

To correct this, I designed a feed-tray-spacer to not only keep the blanks from raising up at the front, but to keep them in line during feeding.
I gave Robb-Walters a copy of this so that he could make (or have them made) these for sale.

Regards, RichardS
US Army, RET
Blanksguy2001@outlook.com
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