Mag drop (mag catch) problem FAQ:
Mag drop problem FAQ (feel free to add/edit):
Q. What exactly is the "mag drop" problem experienced by some with the M&P line of pistols?
A. A fully seated magazine unexpectedly pops out from the frame due to disengagement with the magazine catch after firing a round.
Q. Does this problem occur with only the compact series of M&P pistols?
A. Anecdotal evidence seems to suggest that it occurs more frequently in the compact series of pistols, but it has occurred in both the full-size and compact size of pistols.
Q. What range of serial numbers seem to experience this problem most frequently?
A. No data has been collected outside of S&W regarding this, though this problem seems to have surfaced (reported) for the first time as early as the December '06 time-frame.
Q. How many people have experienced the mag drop problem?
A. Anecdotal evidence from the most recent poll on this forum suggests that nearly 20% of the people responding to the poll have experienced this issue.
Q. How many rounds are typically fired through the pistol before the mag drop problem is experienced?
A. Anecdotal evidence suggests that the number of rounds shot before having the problem varies widely, with some experiencing the problem only after shooting several hundred rounds, while others experience it "right out of the box."
Q. Isn't this just the case where people are accidentally hitting the mag release button under recoil because they are using the wrong grip?
A. While a few posters have reported the occasional inadvertent mag pop out due to one of their fingers accidentally bumping the mag release button, this is a separate issue than what is being described here (see below). After experiencing the mag drop problem for the first time, many posters report of conscientiously checking their grip to make sure that was not the cause.
Q. What are the possible cause(s) of the mag drop problem?
A. Reports have been posted on this forum of S&W reporting a batch of incorrectly manufactured mag catches with an improperly hardened metal mag catch "tooth" as being the root of the problem. However several people have reported that their mag drop problems persist even after sending in their pistol one or two times to S&W to get new mag catches installed. In some cases, only after they have their frame replaced does the problem seem to be resolved. This reasonably leads one to suppose that the problem could be related to the following:
1. The mag catch design used in the M&P pistol line absolutely requires tight tolerances between the magazines and the frame's magazine well, due to the minimum amount of mag catch "tooth" engagement with the corresponding cutout in the magazine. Flexing of the frame during recoil, combined with any free movement "play" of the magazine in the mag well could potentially cause the magazine to disengage from the mag catch. As an experiment, one member reported being able to push out a fully seated magazine from the top of his 40C by wiggling the top of the magazine around and applying a small amount of downward pressure. One could suppose that the lesser occurrence of this problem in the full size models is due to the greater amount of magazine to mag well surface contact area, which by its nature allows less free play of the magazine.
2. Several M&P owners on this forum have remarked that the mag catch spring seems to offer too little resistance to the slightest of depression of the mag release button to get the mag to release.
3. The relatively high profile of the mag release button, coupled with the above, has possibly contributed to several people having reported experiencing their mags popping out while their pistol is holstered. This in addition to the previously mentioned cases where a finger accidentally hits the mag release button under recoil. Some posters report having success in reversing the button to the opposite side to minimize the chance of bumping the mag release inadvertently, either by finger or holster. This is not an acceptable solution to many, however. Some have even resorted to modifying the profile of the button by grinding it down to be more flush with the frame and have reported positive results in doing so. In any event, the opinion that the mag release button is "too easy to hit", especially on the compacts, has been voiced by more than one poster on this forum.
Q. Is there any way to tell just by visual inspection that I might have a mag catch with the problem, like a number "1" or "2" stamped in the underside of the mag release button?
A. There seems to be no correlation between those manufacturing numbers and the mag drop problem. Forum members report having it with either number. However some have reported noticing that the top contact edge of the metal mag catch "tooth" appears to have been visibly worn over, or peened, after only a relatively few mag insertions. The new mag catches are reportedly hardened differently and are not supposed to wear so quickly.
Q. What should I do if I think I am having this problem with my M&P pistol?
A. Contact S&W customer service to obtain a prepaid return shipping label so they can fix it for you.
To be continued...