Mystery Belt Fed Machine Gun Top Cover

[peregrinvs]

I’ve used Evaporust (I have a small can in the garage) and it works well, but from my perspective it is expensive for what it is and doesn’t seem to last as long as the manufacturer implies. I therefore save it for removing rust from small / delicate items and use cheaper rust removal methods for larger or more robust items.

[RCS]

There is a machine gun collector & shooter who goes by the name "Heck in Ohio" who owns a a pair of of MG 81's. Sometimes he posts photos firing these on gunboards

[peregrinvs]

Progress. I started by giving the latch end a soak in Sodium Citrate to clear a patch of clean metal. Then I gave it an overnight electrolysis treatment. There’s some way to go yet, but overall it has worked well. I’m particularly pleased that the maker markings are still clearly legible and I believe they show it is from the left hand gun in a Zwilling mount, made by Wagner u. Co. GmbH of Mühlhausen (gal). Can anything be determined date wise from the 69 747 serial number?

[browningautorifle]

Progress.

Yes, it's coming along.

[peregrinvs]

Yes, it's coming along.

Thank you. I think the law of diminishing returns has hit with the electrolysis so I have finished that and immersed the front half in a bath of Sodium Citrate (pending finding a better container that will take the whole thing whilst minimising wasted volume). It’s bubbling away which hopefully means the remaining rust is being chelated and dissolved.

As you may have guessed, I’m quite enjoying this.

[browningautorifle]

Nice piece, yes the rest was probably just part of wreckage and tossed into the hole.

[stencollector]

Muriatic acid (as used in swimming pools) will remove rust extremely quickly. Neutralize with water and blow dry before it flash rusts. The fumes are a bit harsh, so do it on a windy day outside or use a facemask with an appropriate filter in a large open space. Not recommended for use in an apartment or home.

There may be pitting afterwards, but thats not from the acid, that is the pitting left from the rust process.

[browningautorifle]

Muriatic acid

One of my favorites around here, wondered if it might eat some of this cover but I guess you're right. Steel will take it. Yes the rust just disappears.

[peregrinvs]

Nearly there. I will hopefully soon move onto the dismantling phase which will begin with a long soak in penetrating oil. I was pleased to find (when I gave it an experimental tap with a plastic hammer) that the extractor spring is still strong.

Probably a long shot, but could anyone point me towards some info on how it comes apart? I am aware of a scan of the WWII German operator manual available online which contains illustrations of it taken apart. This is very helpful, but it isn’t quite a dismantling guide and still leaves some guesswork.

PS. Has anyone apart from me spotted the aviation themed serial number? The first flight of the Boeing 747 was in 1969.

[browningautorifle]

I am aware of a scan of the WWII German operator manual available online which contains illustrations of it taken apart. This is very helpful, but it isn’t quite a dismantling guide and still leaves some guesswork.

Honestly? Unless an owner pops up here, I'd order the user manual for the $30USD and go from there. If you have the whole thing it would help. I'm also guessing you have some aside mechanical ability which will help. It's going to be tough because of it's condition.

The link to the manual... German MG Manuals