Proof Research Pre-Fit Barrel for Sig Sauer Cross Features The Proof Research pre-fit barrel for the Sig Sauer Cross begins as a full-profile match-grade 416R stainless steel blank before being turned down to a reduced contour that significantly cuts weight versus a traditional steel barrel. That reduced contour is then wrapped in high-strength aerospace-grade carbon fiber impregnated with a proprietary matrix resin developed by Proof Research s advanced composites division. The carbon fiber wrap diffuses heat along the length of the barrel and moves it through the wall more effectively than steel alone so the barrel cools faster and holds its zero longer across strings of fire. Threaded at 5/8x24 the muzzle is ready to accept a brake compensator or suppressor without additional machining. Because the barrel is pre-fit with the extension already installed a Sig Cross owner can swap barrels quickly and confidently to change calibers or refresh a worn bore without sending the rifle to a gunsmith. This carbon fiber construction cuts up to 64% of the weight of a comparable steel barrel of similar contour making the rifle noticeably more maneuverable in the field. The reduced weight up front also improves balance for offhand and field-position shooting which matters for hunters and competitors covering long distances. The Proof Research pre-fit barrel gives Sig Cross owners an easy path to a lighter cooler longer-lasting .308 Win barrel. Proof Research Barrel Specifications Manufacturer: Proof Research Caliber: .308 Win Barrel Length: 20 Twist Rate: 1:10 Muzzle Thread: 5/8x24 Material: Carbon Fiber / 416R Stainless Steel Color: Carbon Compatible Hosts: Sig Sauer Cross Available At: GrabAGun