I just wanted to make a comment with all the low left problems I've read about. Granted I do not know the backgrounds of the shooters shooting low left, however I recommend you have someone else shoot it. If it is still shooting low left, shoot it off a sandbag rest or the equivalent. Pay close attention to your trigger control. Low left is a very common problem and I believe you should try to see if it is you before you send it to S&W. There is no point in having your handgun sent to them for a few weeks only to get it back and you still shoot it low left. If it is you, then you will need to practice your trigger control to get used to the gun.
FWIW, I still shoot Glocks low left with very tight groups and for my life cannot get it to not shoot low left offhand. The guns do not seem to fit my hand. Have not ever had a low left problem with any other guns or the M&P .40s I have shot. Look into into changing to a different backstrap with the M&P if you have this problem and see how it affects it.
FWIW, I still shoot Glocks low left with very tight groups and for my life cannot get it to not shoot low left offhand. The guns do not seem to fit my hand. Have not ever had a low left problem with any other guns or the M&P .40s I have shot. Look into into changing to a different backstrap with the M&P if you have this problem and see how it affects it.