Product DescriptionThe Ballistic Advantage Modern Series 18" 5.56x45mm NATO SPR barrel is built for AR-15 style rifles and engineered for accuracy and hard use. It is machined from 4150 Chrome Moly Vanadium steel and finished in a corrosion-resistant Black QPQ finish, with a QPQ-coated M4 feed ramp extension. This rifle-length gas, SPR-profile barrel features an extended 0.750" gas block journal/profile dimension designed for proper installation of the OPS Inc. 12th model collar and suppressor.Product Highlights 18" Modern Series AR-15 barrel chambered in 5.56 NATO (commonly compatible with .223 Remington) 4150 Chrome Moly Vanadium (CMV) steel construction with durable Black QPQ corrosion-resistant finish SPR profile with rifle-length gas system for a smooth, performance-focused build Extended 0.750" profile/journal dimension to support OPS Inc. 12th model collar/suppressor installation QPQ-coated M4 feed ramp extension for reliable feedingSpecs Brand: Ballistic Advantage Series: Modern Series MPN: BABL556020M UPC: 819747020147 Caliber/Chamber: 5.56x45mm NATO Barrel Length: 18" Material: 4150 Chrome Moly Vanadium Steel Finish: Black QPQ Gas System Length: Rifle Profile: SPR Twist Rate: 1:7 Muzzle Threads: 1/2-28 Gas Block Journal Diameter: 0.750" Weight: 41 oz Platform: AR-15Disclaimer: 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.