The Rosco Manufacturing Purebred 6mm ARC is a 16-inch, 6mm ARC caliber barrel designed for AR-15 platforms. This barrel prioritizes performance with an SPR contour that's ideal for cold bore shots on target and a balanced weight. Gas ports are optimized for popular precision bullet weights and suppressor use, ensuring reliable function. The barrel features a Rifle Length gas system for smooth operation.Features: Chambered in 6mm ARC 416R stainless steel construction 80 grit bead blasted finish 5/8x24 barrel threads SPR barrel profile Rifle length gas system .750 gas block size Step crown Length: 20" Weight: 35.4 oz.