how to adjust feed lip on mp40 magazine

[NFA amnesty]

I searched this topic and did not see any advice on how to actually adjust the feed lips on a MP40 magazine. Regarding my bad mag, the angel of the round is almost flat causing the round to nosedive and driving the round back into the brass casing. The bullet is hitting on the bottom of my chamber. My other mags run great and can tell the front of the bullet nose is pointed up at an angle.

 

Would like to work on this one magazine and make adjustments so the nose of the bullet is pointed up.

 

Any advice on how to adjust in order to cause the bullet to be angled up?

 

Thank you.

[hawksnest]

could your magazine spring be installed backwards?

[NFA amnesty]

No, I checked a good mag that cycled in my weapon and both the good and bad mag the spring was installed the same way when I compared the two. But I appreciate your advice, that could have been the issue.

 

Believe I have answered my own question but would like others to weigh in on best way to correct. One of the feed lips is bent down at an angle. The other side is almost straight. My good mags, all have the lips almost straight up (slightly bent in). This is causing the angle of the round to be flat on the bad mag.

 

So folks, what is the best way to bend that one feedlip back up? I have vice grips and could use that but thought I would ask before I bubba up the mag.

Edited September 13, 2021 by NFA amnesty

[BRMCII]

Not difficult to use a needle nosed pliers to adjust the angle. The type of pliers that I use have jaws that are slim taper cones and no sharp or serrated edges. Put a small piece of poly over the feedlip to prevent scratching the finish. Use light pressure when gripping the lip and raise the edge of one or both lips to duplicate the angle and match a mag with lips that feeds well. The lips do bend fairly easily and can be reconfigured fairly easily with care.

Buy some dummy rounds for testing the feed in the gun which makes the process much easier and quicker.

Good luck. FWIW

[NFA amnesty]

Not difficult to use a needle nosed pliers to adjust the angle. The type of pliers that I use have jaws that are slim taper cones and no sharp or serrated edges. Put a small piece of poly over the feedlip to prevent scratching the finish. Use light pressure when gripping the lip and raise the edge of one or both lips to duplicate the angle and match a mag with lips that feeds well. The lips do bend fairly easily and can be reconfigured fairly easily with care.

Buy some dummy rounds for testing the feed in the gun which makes the process much easier and quicker.

Good luck. FWIW

Thanks for the info. I have some dummy 9mm rounds so will test when I am done correcting the feed angle.

[TSMGguy]

As mentioned, the magazine should present the top round angled slightly up. The ejector is part of what makes this happen. The rim of the top round should be contacting the underside of the ejector, moving the round slightly forward. Note the angle on the bottom of the ejector in Bergflak's photo below. Note also that the shape of the ejector changed, and there are early and later versions:

 

MP38 and MP40 wear and tear parts (bergflak.com)

Edited September 13, 2021 by TSMGguy

[johnsonlmg41]

I'd probably use one of the sten magazine adjustment mandrels that BRP had for sale. It would be a good start and you could tweak it from there if necessary.

[NFA amnesty]

I'd probably use one of the sten magazine adjustment mandrels that BRP had for sale. It would be a good start and you could tweak it from there if necessary.

 

 

I would purchase one if they had one . I do own a STEN so the tool would come in handy. I will search the web for one, but if no luck will just adjust with some pliers. I have another MP40 mag which looks like a caveman adjusted it and it works but looks like crap.

Edited September 14, 2021 by NFA amnesty