[JimVT]

So, I finally received my backordered full size 40 mags and tried them out on my 40c. After the first shot it would not chamber another round. The mag was becoming unseated after every shot! While trying to work though this it caused no round to be chambered probably 90% of the time. The other 10% was various failure to feed problems cause by the mag dropping. This happened with both magazines. I popped in the standard compact mags and ran through a box with no problems. Has anybody else experienced this? Is sounds like it could be closely related to the mag release problems others are seeing.

 

[coltman1985]

My guess is that you may be applying pressure to the mag and under recoil it is being flexed to the point of releasing itself. Just a hunch!! Try shooting the gun without touching any part of the mag and let us know the results. JMHO :wink:

 

[JimVT]

Interesting theory, I'll give that a try. Is this something that you've heard of before or did you just make it up off the cuff?

 

[JimVT]

So, I just came back from the range. The only mag that worked was the short mag with flat bottom plate. Both full size mags and the standard mag with pinky extension failed. After every shot they released and slid down far enough that another round could not be picked up. Some times there would be failure to eject as the case slid below the ejector due to the extra space in the mag well. I made sure not to put any pressure on the full size mag and all that resulted in was the mag dropping to the ground. Back to S&W for repairs.

 

[Pappy1600]

Sounds like the mag catch to me, mine did the same thing until I replaced the catch and have not had any issues since.

 

[Sigman]

Have your mag springs been broken in? When I got my 40c the flat base would load fine and the mag with the extension wouldn't even chamber a round. After I keep the mags loaded for a few days problem stopped and never came back.

 

[JimVT]

With all the mag catch issues I've read about I think that's likely the issue. Concerning the mag springs I don't think that's it because I went through a whole mag manually re-seating and chambering a round after each shot. Obviously the spring pressure is different for each round removed so the issue was still there no matter what the spring pressure was, first round or last round.