I'm not very smart phone savy...my writing started with... I have had my M&P 9 for six years.... That said..I never had issues with slide barrel alignment...actually...it's very well fitted..and quite accurate with my hand loads...and seemingly un flapable with and without the suppressor mounted. My only concern is that the front of the frame where the light mount's is really thin and doesn't have enough support to keep a good adjustment on the laser. My Glock 41 on the other hand....the front of the frame is kinda up turned towards the bottom of the slide...when the slide goes into battery it actually contacts the top of the frame and keeps the laser on target.. I don't know if all Glocks have these traits....but I wish S&W would have done this with my M&P 9... I think they may have thinned the frame out a little too much to make it more carry friendly...other than that...I still like the..."my" particular M&P 9.