AR-57 Upper Assembly 5.7 X 28 16 Barrel

AR-57 Upper Assembly Features The AR-57 Upper Assembly combines functionality with advanced material technology. The 16 barrel finished in black melonite offers exceptional durability and corrosion resistance while the 1:9 twist rate is tailored for the 5.7x28mm cartridge ensuring accurate and stable projectile flight. The assembly s bolt carrier buffer tube and flash hider all crafted from 8620 steel alloy also receive a black melonite treatment enhancing the overall resilience and lo