When the first one`s came out i bought one `cause i liked the laser design of it , but it started having LS issue`s somewhere around my 300 to 400 rounds fired mark , i couldn't figure it out and talking to S&W back then was a joke so when the M&P version came out and was getting good reviews i traded my old one in on a new one , And , at less than the same rounds fired mark as my old one had it started having LS issue`s worse than the old one ! I was getting 3 to 4 LS`s in every magazine i tried to shoot , but the funny thing is it would shoot the first 3 or 4 mags with no problem , i really was PO`d about this and got back online and seen im not the only one again with issues ! So because i really like this little excuse for a pistol i bought the Galloway trigger kit for it and installed it without the hammer spring because i could hardly pull the trigger with it installed , while i had the slide apart and the firing pin out i polished the firing pin channel and lightly deburred and polished the pin and the blocker bar (i guess its called) and reassembled , now after 150 rounds that varied of different brands i had on hand i only had 2 LS . I dont know what did it , the trigger kit or the polishing but i did notice that when watching the hammer as it is released from the trigger pull ( dry fire with a snap cap ) that it travels in a sort of right to left kind of arc ( i went and looked at a few more at a couple different gun stores and it seems a common thing ) and im wondering if the hammer is skimming on the inside of the slide somehow when things are heated up that's causing LS issues or maybe the blocker pin isnt being lifted high enough ? When you break down the pistol completely and take a good look at how the pistol is made and how it functions you`ll see that it "should" work as designed and reliably at that ,,, im just trying to understand why it doesn't and fix it . I have gotten a little closer i think , from listening to everyone else`s experiences and what they are trying. Thanks for posting your experiences !!!!