CMMG Mk9 9mm Parts Kit

CMMG Mk9 9mm Parts Kit: CMMG has made a small modification to 9mm barrels to be compatible with Mk9 lower receivers. This modification applies to Mk9 platform lower receivers and does not positively or negatively affect functionality of the barrel with MkGs, Mk4 or Mk17 platform lower receivers. Barrels stamped 9mm Luger will be compatible with an upgraded Mk9 lower receiver. If your barrel is marked 9x19 NATO, you will need to purchase a new 9mm barrel for reliable function. Package contents: CMMG Mk9 9mm Parts Kit. This kit is available in two orderable variants: 91AFF43 and 91AFF52.