Due to the limited barrel, the CAR-15 SMGs suffered from a loud and bright muzzle blast, and many muzzle units have been designed to cut back this. The SMGs were originally equipped Together with the typical M16 rifle's "duckbill" or 3-prong flash hiders, which didn't relieve the challenge. In September 1966, Colt designed a 3.5-inch (89 mm) long