MGC MP40 What is possible with mine?

Hi All,

I'm a UK based Firearms owner and recently I was given by a friend a
MGC MP40 which he says he bought around 30+ years ago.

I've already stripped it down and reassembled it.
The magazine won't lock in correctly without a lot of fiddling with the release button.
Even then it will tend to drop out shortly after.
The bolt has had the cartridge face cut at 45 degrees removing the cartridge head seat.
It has a inch long steel removable insert between the chamber and the barrel.
The barrel is blocked and is held on by a large nut with six sides.
The only bit of plastic is the side covers.
All metal work is made of steel.
The magazine will take 9mm Luger rounds!
As will the chamber!

So.... My questions are:-

Does it just need a replacement bolt to allow plug cap things to work?
Does anyone still make and sell a bolt?
Is it only the magazine catch that holds the mag in correctly?

Mark

Hello Mark and welcome to the Forum !

It should be possible to convert your MGC MP40 back to a cap firing shell ejecting model. There are several threads and posts here under the MGC68 MP40 dedicated category discussing how.
Here's just one to start with:

https://mp40modelguns.forumotion.net/t156-mgc-mp40-conversion-to-pfc-firing?highlight=mgc+mp40

Basically, you'll need a replacement bolt, Detonator Pin and MGC P220 OR equivalent cartridges.


The magazine catch is all that secures the mag in place. You may have an incorrect magazine? If you've a standard MGC68 mag it'll be marked as such and may just need a little adjustment to clip in securely.

There's a fair bit of reading on here to catch up on. Have a good read, then get back to us for further info on the finer details and where to obtain parts etc.

Looking forwards to hearing from you,

Hi Cerwyn,

I've managed to remove the mag-well and work out partly the reason for the mag not locking.
Basically the latch twists back at an angle with the mag in unless carefully held straight when inserting the mag.
It appears that a small clip inside allows the latch to move, or it could be that the latch needs a deeper notch in the mag. The mag has "mgc68" stamped on it along with a few other marks. I have since read a post about the notch depth, so I will check this tonight.

The chamber has four holes drilled from the underneath. Two for the mag well screws and two appear unthreaded. I am unable currently to remove the chamber block from the upper as it has several indents holding it in.

I'm unable to find out what the metal thing is that sits between the chamber and barrel.
It appears to just set the chamber depth.
I'll have to take some pictures.
I repaired the plastic side cases, one had the screw hole broken off. A splodge of epoxy solved that.

Oh... I keep forgetting that you have to pull the trigger to remove the upper! Caused lots of agro that did!

Mark

Excellent!
The links showed exactly what I needed to see.
The insert I have is the "plug" which lucky for me is loose and just falls out.
From the picture of the detonation/firing pin, I could see how it replaces the plug.
It also explains how the cap fire system works. Very neat idea that.

My chamber doesnt have any slot cut out, apart from the small notch for barrel location.
The extra holes I can tap a thread in and plug.

This just leaves the bolt...
It has the extractor hook but as mentioned before the cartridge head face has been cut/milled out.

So, I either need to replace the bolt or make a new face insert.
Interestingly, whilst inspecting the bolt, I noticed that it is a cast alloy coated with a tin covering. Some of it had started to peal off in a slot on the side.

Do you know how the ejection worked?
As far as I can see it appears to rely on the extractor holding one side of the case and the recoil twisting the case out at an angle.
Unlike other systems which use a ejector pin/rod/spring or whatever to help the case on its way in the right direction.

Mark

I just had a thought!
If the bottom hole are plugged, the barrel plugged (which mine is), when a cap fires the only place for the gasses to vent is back through the chamber.
Does this not cause a safety issue of hot gasses venting back towards the user?
I remember a browning hipower blank firer i had back in the 90's vented up and forward away from the user.

Mark

Well, I now realise I'm a plonker.
I removed the ejector from the mag well when stripping it down to fix the mag catch.... Forgot to put it back in again!

I shall post pictures of the bolt and everything later and also add info to the register thingy.

Mark

Okey dokey, I'm going to try and put some pictures up...

I have a whole load of pictures, but haven't been a member long enough to post the link.

Anyway...

Just the bolt, a very clear picture of the business end.
Although, looking at it closely, either it is suffering from striking the mag a bit or the cutting of the face was done with a hammer and chisel.



And the complete gun.



Mark

Thank you for the information and the help.
I shall contact the people you mention and hopefully I'll find a bolt and detonator pin.

I only wish my MP40 looked as good condition as the others that have pictures on here.

Mine does have a bit of corrosion on the outside of the barrel and receiver and some dents.

I may have a go at making my own pin if I need to, but knowing my lathe skills it may take a while.

I will keep you updated on my progress.

Mark

used one of these for many years converted to 9mm blank firer, when they weren't silly money to buy

Wow!  

Cerwyn, you really are a wealth of information.

I'll leave the re-bluing until its is working. As you say, a lot of elbow grease.

Looking at the new bolt face, it needs some proper machining.
Not something I am able to do.
My brother could probably knock one up in his tea break, but unfortunately he usually takes several years to getting around to having that tea break!

I'll await responses from the contacts.
No response as of yet, but I live in hope.

Mark