REMOVING MY MGCMP40 Barrel

Does anyone have any words of wisdom on removing my MGC MP40 Barrel...? I don't think it's ever been removed so it's very stubborn... I don't have that original tool that came with the replica and because it's a good thirty years old I'm worried that I might snap the zinc if I'm not careful....

TIA

Yes, sticky parts can be a challenge!
I assume you've checked to see there are NO screws or grub screws etc. drilled into the trunnion underneath (like mine had); in which case I'd use a "liquid wrench" (see link) or similar. Don't use WD40 or CRC, as they won't work the same way.

Give the barrel nut and trunnion area a liberal spray and leave to soak in for 5-10 mins. Then try loosening it gently with a large adjustable spanner (or preferably a spanner that fits without adjusting!).

Repeat if necessary, and if it still doesn't move, soak some more and leave a longer time (say an hour) and try moving it again. A GENTLE tap of the wrench might be needed to "persuade" the nut to start moving - but no more than that, if at all!
Liquid Wrench usually works like magic!

http://www.gunk.com/prod_photo.asp
and a video:

http://www.viddler.com/explore/LiquidWrench/videos/15/

Let me know how you get on.

KG

Thanks for the advice... I'll have at it tomorrow and report back on what luck I have!!!!

There is a grub screw under the trunion... I hate to sound like a dolt but how do I remove this? I have sprayed with liquid wrench to loosen everything up however I don't know how to actually remove the screw as there's no head.

Thanks.

welcome!
It is most likely a metric allen head set screw. You'll need a good set of hex keys. It won't take much to strip out the head on a really small set screw, so make sure you have the proper tool and a good fit, as well as having it sprayed with penetrating oil. Have fun!

Not sure if this will help or not; this is a photo of my MP40.
I made a screw to fit using a piece off a longer bolt with the same size thread. When you get you grub screw out, you'll need to either keep it or make a new one; the hole has to be filled with something if you wish to fire PFC cartridges, if the hole goes all the way into the detonation chamber.

That's a great idea about cutting down a screw to fit...

Does anyone know, did all models have this screw or is it just for the later models to make it more difficult to take off the barrel to convert into PFC firing models?

You may find detailed answers in the MP40 Registry on this forum -

https://mp40modelguns.forumotion.net/modelgun-general-discussion-f1/mgc68-mp40-registry-t886.htm

But. from what I understand it seems that some MP40's had holes drilled and screwed when they were imported into the USA as part of the rendering them un-fireable.
If you check the postings, you'll see that there were many nasty things done to MP40's (like chopping bolts, removing parts, or substituting plugs!).
I'd like to see some photos of your MP40 please! Not sure if you've files details in the Registry yet; if not yours would be a welcome addition.''

I keep saying that I'll take photos and put them up and never do...

I've tried some photos with a phone camera and it doesn't quite do the trick so I'll have to get a new SD card for my "real" camera.

My MP40 has some contradictions. It's the large exposed spring type but the bolt face is intact which is rare from what I understand for the later US import models. There is no serial number and from a cursory glance it appears that the barrel is completely blocked. I want to remove it to check and possibly purchase a hollow barrel and see if I can clear out any necessary blockage in the chamber and then get the proper pin... Doc has already gotten me sorted with the proper plunger assembly because I wasn't crazy about the look of the giant exposed spring.

In any event it's going to be a bit of work I'm sure so be prepared for a lot of questions along the way.

K