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MG08/15 Not Cycling


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Just finished restoration on MG08/15 registered dewat. Test fired it and it fires ejects but does not load a round in chamber. Will load and fire by hand cycling. Ran 20 rounds through it had hand cycle everyone. Recoil action is not stripping a round from the belt. Anyone have a suggestion.

Edited by czerka
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Description of problem is too vague. Cycling by hand does not require the action to recoil fully and the failure sounds like a typical short recoil problem.

First possible source of failure is having the fusee spring wound too tightly which prevents the action from recoiling far enough to the rear.
This means that the rearward motion of the recoil plate/barrel is insufficient for the extracted round to drop down for chambering on the action returning to battery. The extractor horns that ride on the top of the cams on the inside of the sideplates have to reach past the rear end of the cams so the extractor holding the new round drops down onto the axis of the chamber.

If the action is short recoiling, the new round in the extractor will remain in the extractor which is still fully raised and riding on the top of the cams. If the cams have notches at the rear end the extractor horns will catch in those notches and be held there on short recoil. This prevents the round ini the extractor from moving forward when the extractor does not drop down and eliminates the possibility that the point of the extracted round will not thrust forward and ignite the next round in the feedblock.

You need to explain here if the malfunction is the result of the extractor not dropping down on recoil. This is easy to determine by opening the topcover after the failure and observing the position of the extractor. For aim internet diagnosis this is essential information.
With WC MGs that rely on the rearward movement of the barreled action, the water seal packing must be thin enough to allow this action to function properly. If you have packed both the rear of the barrel and the muzzle with packing, and the packing is too thick, it will bind the barrel and not allow the action to move backward.

Was packing used fir shooting the gun? That needs to be revealed.

A simple test is to shoot some rounds without packing and insuring that it will function properly.

Set the fusee spring at the tension that insures that the lock will go back into battery when the cocking handle is released from full rotation. This tension is at a point where less tension and the lock will not got into battery when the handle is released, but stops at the point where the firing pin spring compression is reached on the locks return to battery, and if more tension is added, the lock will go from full drawback into battery. Too much tension on the fusee spring and the recoil of the recoil plate/barrel will not be able to sufficiently recoil for function.

So, I'll leave it at that and wait for more detailed description of the condition of the gun as requested above. There is info in Dolf's Maxim books and probably a number of you-tube videos addressing these issues.

FWIW

Edited by BRMCII
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Thank you for your response, I am thinking that it is likely a recoil issue. There isn't any packing. When I got the gun it had been painted with black spray paint, pretty thick. I stripped it and hot blued it. So I am assuming any packing material that may have been there would have been removed by either the paint stripper or the actone it was soaked in. The booster is a repro made by Adco, from what I can tell its made exactly like the original. I took the booster off yesterday and did a pogo test like on an MG42 and it seem a little ruff. I opend the cover and checked it after firing it several times and the lock appeared to be at the top of the stroke, the fuzzee was set to 20 during test firing. I ordered a copy of The Devil's Paintbrush yesterday. I am going to try and disassemble it and see if I can't get the barrel assembly moving more freely before I test fire it again.

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Try using a cheap fishing weigh scale from Walmart to test how tight are the recoiling parts. Handle in up position then pull straight back, should be about 8 lbs. The book also explains how to do this. Good luck.

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With all due respect, in order to really get much useful information about what you need from the users of this site, the first thing you must do is to study how the mechanics of the action work and thoroughly familiarize yourself with it. Without knowing how the action works, and the specific names of all the parts it is very difficult to to understand clearly what is happening with your gun. For example, there are a limited number of malfunctions that have to do with the fusee spring tension and it's relationship to recoil issues and the function of the lock and which are common and easily diagnosed once you understand how the system works and can convey these issues using the correct terms, etc.

Dolf's book has an excellent section on diagnosing malfunctions as well as everything you need to learn about the names of the parts, and how they operate individually and as a system.

There are mechanical events, when the system is operating, that can't be discussed without the participants understanding exactly which parts are involved and how they function at every position in the chain of events of the specific action, especially with the function of the lock.

Plus, there are various tricks that can be used for setting specs for proper function of the action, etc which will make much more sense and be useful once you have a good hands-on familiarity with the gun, it's design, etc, etc.

They are fascinating machines and great fun to handle, maintain, shoot and admire. I've been addicted to them for close to forty years and at last count, have 25 of them. You are a lucky guy to own one!!

Keep in touch on this site and others. FWIW

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What he said is very true, you will spend more of your time tinkering and studying about this gun then you will ever spend shooting it. Lots of history and knowledge needed to understand these guns since they are the first generation of machine guns. Like the Chauchat they work if you put a lot of time and effort into them. I have taken apart and put mine back together about a hundred times, good times on a cold winters night in my basement.

Edited by waterdawg2004
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