04/30/2025
For those of you who take their MP40 apart frequently to clean it, here is something to keep an eye on.
The furniture as we all know is plastic. Plastic tends to wear in areas where fasteners are involved. Case in point are the four holes that are used to secure the furniture to the weapon. As we remove and install these screws time and time again, the countersinks will eventually allow the screw to go deeper. The tighter they are installed each time the faster this happens. I want to point out that the furniture on my MP40 is not the factory set it came with. Hopefully the GSG is more durable and will not wear as fast.
What happens when the screws go to deep? Nothing for three of them, but the right front furniture screw is another story. If this screw goes deeper than it should, it puts pressure on the hammer assembly which is directly under it. This causes the trigger not to fully return to allow a reset for the next round. I noticed this at an event this past weekend.
The pictures don’t really show it the best, but after taking it apart 4 times I was done.
A test fire of a full magazine of Canadian blanks proved to fix the problem. I also had light strikes with this condition. Those are now gone. Not sure if the two are related, but the MP40 is running like a top again.
