Issue with my Beretta
 

So ive been having this issue with my .40 PX4 Storm sub compact. Sometimes when firing the last round, the slide bites into the hard plastic of the magazine and fails to lock in the retracted position as it normally would when no rounds are left in the mag. You can see where the metal is catching the plastic but i dont know how to make it function smoothly. It apears to only happen with on of the mags. Any advice, ideas, or similar issues?

Compare the mags (even under a microscope).

I would purchase a new mag as a replacement.

I suppose i could just order a new one or two. That would be the best indicator to show if it is this mag or and issue with the gun itself.

If it did that same malfunction with all mags, then I would consider the firearm.

Anytime you get (or have) multiple mags, number them. When a problem arises with the mag, it is easy to tell which for sure.

Oh that's a really good idea. Thanks!