One thing that has always set the AR15 platform apart from many of its rivals has been modularity. With the 9mm DISSENT available in the Mk4 platform, shooters have a 9mm pistol that can use the CMMG 9 AR Conversion magazines. These magazines feature the same profile as 5.56mm magazines for a familiar manual of arms and true double stack feeding from top to bottom for fast and easy loading. 9mm ammo loadings can vary greatly, from supersonic to subsonic. With a wide range of bullet weights comes new engineering challenges in a new platform.