Shop › ROSCO K9 BARREL/HATCHET 5.56 INT GAS ROSCO K9 BARREL/HATCHET 5.56 INT GAS $225.00 Rosco Manufacturing K9 Barrel, 556NATO, 16", Intermediate Gas System, Fits AR-15, Melonite Finish, Black K9-16-HY-556-7-I Quantity: Add To Cart Added! Rosco Manufacturing K9 Barrel, 556NATO, 16", Intermediate Gas System, Fits AR-15, Melonite Finish, Black K9-16-HY-556-7-I