blank adapting the mg42/m53/mg1-3

Blanking adapting the MG42, MG3 and MG34
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Re: blank adapting the mg42/m53/mg1-3

Post by blckwlfny »

I'm not sure about that specific problem, but it may be due to short cycling. I had a problem originally withy the cases folding UNDER the barrel, but it became aparent that this only occured after a double feed. Sometimes becasus the plastic cases have no real mass, they will not fall out the port fast enough. There must be a substantial hit on the ejector to "fling" the casing out.
I solved it by placing a small spring in the front of the buffer assembly. It has to be stiff enough to eject hard. Soft enough to fold when there is a lot of recoil. Long enough to engage the ejector early and short enough to not eject before the port. The OD must jjust about fit in the ID of the buffer. Ill see if I can find the exact spring that I used and post a link.
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Re: blank adapting the mg42/m53/mg1-3

Post by blckwlfny »

I tried to post a pic, but I can't get my camera to talk to my computer.
Sorry. I found the exact spring though
http://www.mcmaster.com/#catalog/119/1215/=o1nqhu
It is item# 9657K315
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Re: blank adapting the mg42/m53/mg1-3

Post by blckwlfny »

Got the camera to work. Here are the pics. Friction holds the spring in mostly. But I used a dab of silicone at the base just to be sure. Not my preferred method, but easy, effective. And reverseable.
2013-08-14 06.27.42.jpg
2013-08-14 06.26.28.jpg
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Re: blank adapting the mg42/m53/mg1-3

Post by sokerivatsa »

This is exactly what I thought would work. I'm gonna look around for springs over here, in stead of ordering from overseas but I will keep it in the back of my head. I tried piecing a pipe to do the same but this is sure to work way better. I will give more updates as we work down.
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Re: blank adapting the mg42/m53/mg1-3

Post by blckwlfny »

Take a look at the link. It tells you the spring resistance in lbs. I found that stiffness to work very well.
Also, if yours is fjull auto, I'm sure it will affect the cyclic rate as it shortens the distance the bolt must travel...but then again also slowly absorbs the recoil before the buffer...hmmmm???
Let me know how it turns out :)
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Re: blank adapting the mg42/m53/mg1-3

Post by 42rocker »

Interesting butt stock. Thanks for sharing the pics

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Re: blank adapting the mg42/m53/mg1-3

Post by Blanksguy »

You may have to watch out for a "runaway" gun if the additional buffer-tip spring does not allow the bolt to come far enough back to allow the sear to catch the bolt.

Questions still come up on the use of the buffer-tip-spring as shown in the photo......and no locking-rollers on the Bolt-Head:
1: Bolt travel distance effected (?).
2: Could other "fixes" (Ideas) be tried (?).
3: The checking for wear/changing....and possibly the modification of the ejector "spoon" inside the bolt-carrier to accomplish the same ideas (?).

Some of the issues when using the weaker plastic-blanks are that they not loaded to the same quality of live-ammo.......(IE: The loadings are allowed to have a wider range in differences from lot-to-lot and in a lot of cases, whin the same "lots".).
In addition to this, the operational "pulse" of the weaker plastic-blanks may not have the required duration of "pressure" using the buffer-tip-spring without other modification (?).......possibly to even include weight reduction of carrier-assembly (?).

Have either of you tried the 2-pcs. Blank-Barrel-Assemblies..........(?).......and what were your results when using a bolt with locking-rollers on the bolt-head (?).

Regards, RichardS (Temp. in SA, TX.).
US Army, Retired.
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Re: blank adapting the mg42/m53/mg1-3

Post by sokerivatsa »

currently I am using a 2 piece blank firing barrel and am using the rollers in the bolt again.
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Re: blank adapting the mg42/m53/mg1-3

Post by blckwlfny »

Re rollers and 1 peice: NEVER cycled with blanks despite the work and experimentation of myself 3 gunsmiths and a marine armorer...polishing,lapping,adjusting orifices.
Re 2 piece barrel: I tried it, it didn't work unless I used EXPENSIVE blanks....don't know what's up with mine. It worked without a hiccup live.
Re "seer" ...good point! Mine is not full auto. The problem with these blanks is inconsistent powder loads. The trick with the additional spring is to eject those few that don't full cycle. The spring must be hard enough to egage the ejector, but soft enough not to stop full bolt travel. The theory is that In the event that one of these blanks, does not send the bolt back far enough, the next one probably will....once again it works great in a closed bolt semiauto; I'm not sure the required travel to engage the lugs in a F/A.
Re "wear": Wouldn't the new spring soften the recoil and removing rollers reduce the strain on the locking system? I specifcally used a spring such that when ALMOST fully compressed, it sits below the face of the buffer assembly, so it never reaches the point of failure.
I know the bolt face is not slamming into battery too hard because the plastic blanks would fail, and they're not coming out crushed.
I'm bypassing the recuperator and the barrel bearing.
I know I'm in uncharted territories, so are there other potential problem areas?
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Re: blank adapting the mg42/m53/mg1-3

Post by Blanksguy »

You are correct.....the plastic-blanks are not as consistant.........and your comments about 1-pcs. and 2-pcs. Blank-barrel-assemblies are noted.

So that we do not mislead readers......the MG42 system requires "firing-pressure" to operate with blanks. The less weight that is required to be moved, the less presure from the blank that is required to move that weight........this is where the 2-pcs. Blank-Barrel-Assembly comes in. It requires less weight to be moved.

The issues with your gun may be of another nature.......such as the weight or drag of parts in your particular SA42 may be using more "pressure" from the blanks than other like SA42s (as each gun is different.). The reason that your SA42 operates with live ammo (and the more expensive Blanks) is that these operate at higher pressures.
Basically, if it doesn't move....you need to find out why and correct the system by either fixing a dragging-part or make the moving-parts lighter..............the going to a smaller "restriction" in the muzzle is the third part of the "system".

Last........just to insure that there are no misunderstanding of Blanks:
1: Not all Blanks are loaded to the same pressure.....so you can't mix Blanks on the same belt.
2: Less weight trequired to be moved lets you have a bigger restriction/hole-size at the muzzle = more noise.
3: YOU ARE NOT GOING TO MAKE THE CHEAP PLASTIC BLANKS ANY LOUDER THAN THEY ARE LOADED......you can only make small changes by lightening what has to move. Maybe to locking-roller removal will work.....but I will address that in the next posting.
4: I would not use a 2-pcs. Blank-Barrel-Assembly with a bolt with the locking-rollers removed......it is a waste of a good 2-pcs. barrel cause it doesn't move.

Regards, RichardS (Temp. in SA, TX.).
US Army, Retired.
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Re: blank adapting the mg42/m53/mg1-3

Post by sokerivatsa »

I can't find a spring (or order one) that fits in the rear buffer. I've tried something else. My problem is the ejection, the bolt doesn't slam the buffer hard enough to eject, resulting in stovepipes.

I dissasembled my bolt and tried to think how I would eject earlier.. I thought to lengthen the ejector rod. But this would mean a permanent change to the device. So I thought putting in a few coins inside the very rear of the bolt. I've tried it without the recuperator and it ejects sooner then before and only with a gentle touch to the buffer. Fine, you'd think. Now i've drilled holes in the coins so the recuperator can easily sit in place. Let's try that out this weekend!
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Re: blank adapting the mg42/m53/mg1-3

Post by Blanksguy »

sokerivatsa,

Earlier you stated that you were using a FA MG42....2-pcs. Blank-Barrel-Assembly with a 3.5mm Restriction for operation...........am I correct so far (?).

With the .308 Blanks (7.62x51mm Blanks).......are you using 8x57mm Belts....or the Post-War 7.62x51mm/.308 belts (?).

Next.......is your restriction in the muzzle (?).....or did you put it in the Booster-Cup/"Nozzle" (?).
What happened when you tried a smaller size restriction than the 3.5mm restriction (?).....and what sizes did you try that were smaller (?).

Do you have a replacement ejector-rod and "spoon" (the long ejector-spoon inside the bolt-carrier) to try switching these out to see if your parts are worn (?).

Regards, RichardS (Temp. in SA, TX.).
US Army, Retired.
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Re: blank adapting the mg42/m53/mg1-3

Post by junglewalk »

I may have missed it, but shortening the recoil spring may be the answer;>> It will allow the bolt to go to the rear well enough, so it will hit the buffer hard enough to eject the empty case, and will return foward with enough force to go into battery, etc......
.......In Folke's book, he recounts in the MG-34 section the difference between the recoil springs for blank fire vs. live fire......I assume it was the same when it came to MG-42 blank firing for training.
......I've done exactly the above on both sa & fa MG-34s & 42s, when it comes to either the 308 blanks, & homemade 8mm full size blanks filled with 14 grs of the fast burning powder, Bullseye.
......I know I have pointed this out on this site in the past, but well worth repeating. :cross:
.......[one coil at a time, until the bolt cycles properly]
......(BTW, when will the MG-42 be returned to the heading above???)...bh
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Re: blank adapting the mg42/m53/mg1-3

Post by sokerivatsa »

Image
Lengthened the ejector rod, should work. I dry tested it and it worked like a charm.
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Re: blank adapting the mg42/m53/mg1-3

Post by Blanksguy »

......and the other requested information (????).

Regards, RichardS
US Army, Retired.
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Re: blank adapting the mg42/m53/mg1-3

Post by sokerivatsa »

Blanksguy wrote:sokerivatsa,

1 Earlier you stated that you were using a FA MG42....2-pcs. Blank-Barrel-Assembly with a 3.5mm Restriction for operation...........am I correct so far (?).

2 With the .308 Blanks (7.62x51mm Blanks).......are you using 8x57mm Belts....or the Post-War 7.62x51mm/.308 belts (?).

3 Next.......is your restriction in the muzzle (?).....or did you put it in the Booster-Cup/"Nozzle" (?).
What happened when you tried a smaller size restriction than the 3.5mm restriction (?).....and what sizes did you try that were smaller (?).

4 Do you have a replacement ejector-rod and "spoon" (the long ejector-spoon inside the bolt-carrier) to try switching these out to see if your parts are worn (?).

Regards, RichardS (Temp. in SA, TX.).
US Army, Retired.
1 Full auto, blank barrel, 2 part barrel.

2 .308, plastic blanks. Wartime belts.

3Booster cul/nozzle is in place. Smaller Restriction in barrel means no cycling rounds. 3.5mm gave me the best results so far, bigger doesn't cycle and smaller gives less rounds that cycle. I've tried 5 to 2 mm with differences of 0.5mm

4 I've tried that, but no result. I've reffered them next to unused pieces and there is no wear on them...

Kind Regards,
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Re: blank adapting the mg42/m53/mg1-3

Post by Zamex »

Hi, I would like to ask you guys for an opinion. I have a M53 with two-parts barrel and I need to fire those grey plastic blanks. I am struggling with it for three years. Now I have a new barrel, with smooth chamber front so it is not chopping ammo on entrance. But still it does not fire, or very seldom. My gun is crushing the ammo - the metal end is facing down and it stops there. Also from on both sides of the ammo there is a strong cut on the metal back part. I dont know if it is related to the broken cartridge, I guess not. It seems as if the bottom part of the case is pushed forward by the bolt but something is slowing it down on the top part? The only thing I can think of is the belt, but I really dont know. I use yugo and german postwar black 8mm belts. Any help really appreciated, I am more than desperate after all the years and money I put into.

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Re: blank adapting the mg42/m53/mg1-3

Post by sokerivatsa »

Testing 3 other mg42/m53's fire plastic blanks flawlessly with my bolt, barrel, buffer and tray/cover I am a bit dissapointed. I've tried absolutely everything to get my gun firing but it's not working.

Should I get another receiver? The rails in my Receiver seems to have minor dents in them. But they are just very minor.
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Re: blank adapting the mg42/m53/mg1-3

Post by 42rocker »

On all of this -- check your receiver outside measurements. Outside should measure 2.2 inches in the rail area. Why check?? Many times the receiver is squished during the rail rivet install or from something else. Less than 2.2 inches can cause the bolt to drag.
Good Luck to all.

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Re: blank adapting the mg42/m53/mg1-3

Post by Zamex »

My receiver meausrements are OK. I testfired with live barrel live ammo and works like charm. But those are brass one-piece casings. What could be causing occasional breaking of those plastic rounds?
Is it necessary to widen belt links, would that help?
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