416R Gun Barrel Quality Stainless Steel Match Grade drop in barrel Final dimension of +/- .003" for consistent accuracy SAAMI spec. 9mm Match chambers 1x10 Twist Rate Sig P320 Black Nitride Finish for durability without hindering performance "SIG" and "P320" are federally registered trademarks of Sig Sauer, Inc. and are two of many trademarks owned by Sig Sauer, Inc. Grey Ghost Precision is not affiliated with nor endorsed by Sig Sauer, Inc. Mfg: Grey Ghost Precision