LanTac USA LLC 9INE, Barrel, Bronze, Threaded Barrel, 1:10, Fluted, Fits Glock 19 01-GB-G19-TH-BRNZ Professional upgrade drop in barrels for Gen 3 & 4 Glock 19 Pistols. Match Grade barrels are precision machined from Certified pre hardened DFARS compliant 416R chromium gun barrel quality stainless steel" to extremely tight tolerances and exacting details. 416R stainless steel is renowned for its corrosion resistance" machinability and high tensile strength" it is the industry standard for Match Grade barrel manufacturing. Lantac's machining and production process delivers an ultra-precise barrel with tightened slide fit & lock up for improved accuracy. 6 groove" cut rifled" 1:10 Twist Right Hand" fully inspected" double honed (rough and finish) to produce a bore with a Max Roughness Average (RA) of 12. Chambers are Match Grade SAAMI specification" precision cut and polished to a maximum Roughness Average (RA) of 16. The pre hardened 416R stainless steel is stress relieved to a proprietary recipe after rifling and final hardness is 38-42 Rockwell C before final shaping and profiling work is done. Final dimension is held to a +/- 0.0002" deviation for maximum consistency" accuracy and quality. Barrels are bead blasted to create a satin finish prior to plating. 9INE Barrels are a drop in fit and do not require gunsmithing for assembly. These are an ultra accurate and extremely tough upgrade. Barrels are fluted and feature LANTAC's proprietary Patent Pending flute pattern.