Technical Specifications Handgun Type: G19 Barrel Caliber: 9mm Barrel Profile: Flame Fluted, Drop In (Compatible with Gen 1-5) Barrel Material: 416-R Stainless Steel Barrel Twist: 1:10 Muzzle Thread: 1/2x28 TPI Crown: 11-degree Target Crown Rifling Method: Button Rifled, Fully Stress Relieved Rifling Type: Conventional  Inside Finish: Salt Bath Nitride Outside Finish: Salt Bath Nitride & Chameleon (Rainbow) PVD *Note - Individual appearance may vary on Chameleon finished barrels. Variations may appear between barrels on concentrations of colors.