Product Description The PROOF Research AR-Style Carbon Fiber Barrel in 6mm ARC represents the relentless pursuit of excellence in precision barrel manufacturing. Built around a full-profile, match-grade 416R stainless steel core, this 18-inch barrel is turned down to a significantly reduced profile to shed weight, then wrapped with high-strength, aerospace-grade carbon fiber impregnated with a proprietary matrix resin developed by PROOF Research ACD. The carbon fiber composite construction reduces weight by up to 64% compared to traditional steel barrels while uniquely diffusing and transporting heat through the barrel wall for cooler, longer-lasting performance. With a rifle-length gas system, a .750-inch gas journal diameter, and 5/8x24 muzzle threading, this barrel delivers match-grade accuracy and unprecedented durability for the most demanding AR-platform applications. Product Highlights Up to 64% lighter than traditional steel barrels, thanks to aerospace-grade carbon fiber composite over a 416R stainless steel core Match-grade accuracy with a 1:7.5 twist rate purpose-built for the 6mm ARC cartridge Superior heat dissipation technology minimizes point-of-impact shift during sustained, high-volume fire Rifle-length gas system with .750-inch gas journal diameter and 5/8x24 muzzle threading for broad AR-platform compatibility Reduced harmonic barrel vibration and unprecedented durability for performance in the harshest environments Specs Brand: PROOF Research MPN: 128671 UPC: 843068128671 Caliber / Cartridge: 6mm ARC Barrel Length: 18 inches Twist Rate: 1:7.5 Gas System Length: Rifle Gas Journal Diameter: .750 inches Muzzle Threads: 5/8x24 Barrel Material: 416R Stainless Steel with Aerospace-Grade Carbon Fiber Wrap Finish: Black Carbon Fiber Barrel Contour: Medium Weight: 1.14 lbs Platform: AR-Style Quantity: 1 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.