AR57 ULT Complete Upper Assembly - 5.7x28mm - 12"

The AR57 ULT Complete Upper Assembly, chambered in 5.7x28mm with a 12" lightweight barrel and M-LOK rails transforms any AR-15 lower into a 5.7x28 firearm. Featuring a unique top-loading design that ejects downward through the AR-15 mag well, this lightweight upper features a stronger, lighter rail with a melonite black coating. The steel barrel, muzzle brake, bolt carrier group, buffer, and screws are integrated into an alloy monobloc receiver for durability. The 8620 alloy bolt provides reliable performance. This upper includes an ultra-lightweight barrel, proprietary buffer, ambidextrous magazine release, reversible charging handle, M-LOK handguard, and a 50-round magazine.

Features:

• 5.7x28mm with 12" lightweight barrel and M-LOK rails
• Converts any AR-15 lower to shoot 5.7x28 ammo
• Top-loading design with downward ejection through AR-15 mag well
• Strengthened, lighter rail with melonite black coating
• Steel barrel, muzzle brake, bolt carrier group, buffer, and screws integrated into alloy monobloc receiver
• 8620 alloy bolt
• Efficient ejection of spent rounds through lower's magazine well