CMMG's 9 AR Conversion makes it possible to shoot 9mm ammunition from your unmodified AR15 lower receiver when paired with a CMMG 9mm Radial Delayed Blowback upper. - CMMG's 9 AR Conversion is inserted into a Gen 2 or Gen 3 Magpul PMAG. It seats into your AR15 mag-well and holds up to 30 rounds of 9mm ammunition. Its unique design allows it to feed any CMMG 9mm Radial Delayed Blowback upper receiver while maintaining last round bolt hold-open functionality. - 9