BSF Barrels Pre-Fit Bolt Action Weatherby 307 6mm Creedmoor Threaded AR Barrel 5/8x24 1-7.5 18in .930 Strait Black/Stainless. They use this jacketing method rather than wrapping the barrel in carbon fiber because this method of wrapping has been proven to trap heat and cause delamination. The carbon fiber they use is specially designed to move at the same expansion rate as 416R stainless steel. They machine slots into the carbon fiber allowing air to move around the barrel and vent heat quicker without any delamination issues. Using the Carbon Fiber this way keeps the rifling straighter the warmer the barrel gets because it's under tension. This allows they to maintain superior stiffness and strength while keeping the barrel extremely lightweight. Specifications for BSF Barrels Pre-Fit Bolt Action Weatherby 307 6mm Creedmoor Threaded AR Barrel: Manufacturer: BSF Barrels Color: Black/Stainless Finish: Carbon Fiber Caliber: 6mm Creedmoor Barrel Material: 416R Stainless Steel Barrel Twist Rate: 1-7.5 Barrel Profile: Contour Threads per Inch: 5/8x24 Gun Make: Weatherby Gun Model: Weatherby Model 307 Country of Origin: USA Package Contents: BSF Barrels Pre-Fit Bolt Action Weatherby 307 6mm Creedmoor Threaded AR Barrel What firearm models does the manufacturer say BSF Barrels Pre-Fit Bolt Action Weatherby 307 6mm Creedmoor Threaded AR Barrel is compatible with? The manufacturer suggests that BSF Barrels Pre-Fit Bolt Action Weatherby 307 6mm Creedmoor Threaded AR Barrel is compatible with Weatherby Model 307BSF Barrels SF3IYT1147: Pre-Fit Bolt Action Weatherby 307 6mm Creedmoor Threaded AR Barrel 5/8x24 1-7.5 18in .930 Strait Black/Stainless