First of all, this is my first post. I have a number of S&W revolvers, but my 40 Shield (which I bought last Thursday) is my first auto pistol (although I have a US Army Remington Rand M1911-A1).
I've had my eye on a Shield for awhile, but had been waiting for my LGS to get some in. They finally got in some, as part of their annual S&W handgun sale. I had done a good amount of web research, but somehow didn't get wind of the mag drop problem until after I bought the 40 Shield. This is probably due to most of the reviews having been done on the 9 Shield. I probably would have waited for the issue to be fully resolved, if I had known in advance of the purchase.
I haven't gone to the range yet, but have been reading through the threads. I'm an engineer by training and vocation and decided to approach the matter in the following manner.
My gun is one of the newer "HAD#### serial numbers. Both mags seat with a solid, clearly audible click. In reading through the posts, I also thought there was too much play between the mags and the gun, which was causing the extended mag to slip out of the mag catch during the post-firing recoil.
Since the mag catch is on the right side of the mag, I laid down three layers of Scotch plastic tape (it comes in a multiple-pack with various colored rolls) to the back and forward left sides of the metal part of the mag. This removes the excessive play and forces the mag catch notch further toward the mag catch. I prefer this method to the punch method that has been discussed. I put the tape on both mags.
Both mags now feel real tight inside the grip section of the gun and seat very firmly. I will test the fix at the range, of course. Until the issue is fully resolved, I won't use the extended mag for concealed carry, but may use it as a back-up clip, if the range testing is positive.
I will use one of my tried-and-true S&W revolvers as my primary CCW for the time being.