I received the two Lancer L5 30rd mags today and they fit my S&WM&P-15Ts magwell perfect. I loaded both full and they snapped in place and dropped free. I sure did not need to be told my mag well was not correct or I could just grind off some of the mags rib to make the mag fit or I could send my lower back to S&W for reworking. This is what some other non-metal mag Mfg. had told me I could do when their mags would not lock into my Smiths mag well. And I sure did not want to do any of the above. I am looking forward to fire testing the Lancer L5 mags IMHO their quality mags.