MP40 ... Non- folding stock

[Harvington]

Just encountered a problem with my MP40.

 

The shoulder leaf won't close down - it stubbonly remains at right angles to the arms, and I'm scared to force it. Has anyone encountered this problem before and identified a solution?

 

Alternatively, does anyone know how to disassemble this component? It looks like there is cross pin at the end of each stock arm that could be driven out to allow the shoulder leaf to come off the end and be reset, but if I do this, I'm worried that the pins won't stay in place when I put them back.

 

Any help gratefully received ...

[Maxim]

Have you tried some oil at the pivot points? They can be very stiff.

[Petroleum 1]

There are a couple of spring loaded pins that engage when the shoulder rest is flipped open. You could try some penetrating oil and give it a good wiggle to break it free. Its not a problem to tap the pins out and service it. If the pins are snug now they will tap back in and stay no problem.

[BRMCII]

The butt plate only folds in one direction, just for a reminder.

Apply some heat to the area around both plungers with a propane torch (you don't need anything hotter than that) and heat until any oil in the parts starts to exude. Don't need to heat much more than that. While hot, try to flex the joints and plungers. If it is still stiff, introduce some oil into the plungers while it is still hot and keep trying to flex it. It should loosen up.
I had a lot of these apart for one reason or another and there really isn't anything mechanical that can go wrong without some serious evident damage and aside from rust or broken springs. FWIW

[TSMGguy]

Right, I'd try heat sweating some mobility into these two assemblies before trying anything else. Keep in mind that the shoulder leaf hinge pins are staked in place. If removed, they must be re staked or they can be easily lost.

 

Bergflak used to sell original MP40 parts. Wonder if he still does? Here's a link to the appropriate parts:

 

https://www.bergflak.com/mp/bs16.html

[colt21a]

CHECK WITH TOR IN KENTUCKY THEY SELL STOCKS PARTS SINCE THE GUNS NEVER GOT DONE HERE OR IMPORTED. GOOD LUCK RON K.

[Harvington]

Thanks for all the replies. It's like having a bunch of Waffenmeisters on speed-dial. 🙂 I'll start with the oil, then the heat, and see how far I get.