Product Description The TacFire SSBU55610 is a purpose-built AR-15 upper receiver assembly chambered in 5.56x45mm NATO, designed for shooters who demand reliable performance and durable construction. Featuring a 10.5-inch M4-profile barrel with a carbine-length gas system and a 1-8 twist rate, this upper is well-suited for short-range precision and versatility with a wide range of projectile weights. The barrel is finished in Black Nitride for superior corrosion resistance and extended service life. A 10-inch M-LOK ATLAS S-ONE handguard provides a lightweight, low-profile platform with ample accessory attachment points, while a 1/2x28-threaded muzzle comes equipped with an A2 flash hider. This complete upper receiver assembly is a capable, ready-to-run solution for AR platform builds. Product Highlights 5.56x45mm NATO Chambering: Compatible with both 5.56 NATO and .223 Rem ammunition for broad versatility. 10.5in M4 Profile Barrel with Black Nitride Finish: Delivers durability and corrosion resistance for long-lasting performance. 1-8 Twist Rate: Stabilizes a wide range of bullet weights for enhanced accuracy and flexibility. 10in M-LOK ATLAS S-ONE Handguard: Lightweight and rigid rail system with M-LOK slots for attaching lights, grips, and other accessories. Carbine-Length Gas System with A2 Flash Hider: Proven, reliable operating system paired with a standard 1/2x28 threaded muzzle device. Specs Brand: TacFire Model: SSBU55610 Caliber: 5.56x45mm NATO Barrel Length: 10.5 in Barrel Profile: M4 Barrel Twist Rate: 1:8 Gas System Length: Carbine Length Muzzle Threads: 1/2x28 Muzzle Device: A2 Flash Hider Handguard Type: M-LOK ATLAS S-ONE Handguard Length: 10 in Finish: Black Nitride Material: Steel Compatible Platform: AR-15 / AR Platform Color: Black UPC: 729205658884 MPN: SSBU55610 Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer. ]]>