I just purchased a new M&p 9mm and been having some magazine issues. The pistol came with two magazines and one seems to enter and exit the magazine-well flawlessly. The other magazine needs to be forcibly hit into the well so it will lock in and must be pulled out because it gets stuck. If anyone knows how I could fix this, or has had similar problems, please let me know what you did.

Thanks,
Will

Check the markings that are stamped on your magazines they should both be stamped 9mm it sounds as if you have a 40/.357 magazine which is just a little wider than a 9mm magazine, take a tape measure and check the widths of both magazines, if they are not identical then you most likely have a mis stamped magazine!

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59,M&P9,40,40C,357,(2)45,G26

I checked the stamps and the width of the magazine, they are both the same. I didn't notice this before but the slide doesn't lock back on the empty magazine that sticks in the magazine well. Does the spring retention in the magazine have anything to do with how it pops out of the pistol?

You seem to have a problem with that one magazine it could be warped or bowed causing it to not operate properly, when your magazine is empty the magazine follower the little nylon or plastic piece is supposed to push up on the slide stop and leave the slide open, this is not what is happening, I would contact Smith &Wesson and let them know about the problem they most likely will send you another magazine without you having to do anything else!

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59,M&P9,40,40C,357,(2)45,G26