ok I hate to do this couse I love my COBRAY M11/9 but all my Cobray Zytel mags have split and the fead lips where out. I have tried the steal shims and they dont improve things much. Of the 6 Zytem mags I have only one still works and only becuse of tape. The steal mag was the one that came with it is old and beat and is still going strong. I have been very carefull with the Zytel I am a very long time fire arms owner it seems to be a fualt with how the seams are put together.