Sent my M&P 45c back to S&W for repair today . Slide will not stay open after last shot fired . Maybe the mags ,they do not fit flush with the bottom of the grip when fully loaded and are sloppy as hell when in the pistol empty. i also asked them to look at the trigger as it seams hard,heavy,stiff,and gritty after 150 to 200 rounds . one of the mags will not always bringup the last round,like the spring or follower is bound up . Yes the mags are clean inside .Hope they can resolve the problem .