The Firing Line Forums - View Single Post - 5.56-.223 Mags & First AR

Metal god · September 4, 2012, 12:18 AM

That notch in the barrel is so you can attach a grenade launcher to it . I believe it's a Mil-spec barrel or the same type of barrel thats on the military issued rifles .

September 4, 2012, 12:18 AM	#42
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 1,022	That notch in the barrel is so you can attach a grenade launcher to it . I believe it's a Mil-spec barrel or the same type of barrel thats on the military issued rifles .