Shilen Drop-In Match AR-10 Barrel for 308 Winchester. 24 inch Heavy Varmint Contour with 1:10 twist, stainless steel. Drop-In LFAR design with a bolt assembly matched to the barrel and headspace set for proper fit. Gas-block shanks machined to +/- 0.001 inches for proper fit. Barrel is uniquely numbered to match its corresponding bolt. Designed for precision and competition use in AR-10 platforms.