Agency Arms Mid Line Match Grade Drop-In Barrel Fluted Glock 19 Stainless Steel. In fact these barrels are machined with the tighter tolerances necessary to ensure a consistent accuracy throughout the lifetime of the barrel. Forged from 416R stainless steel these barrels also feature seven machined flutings around the circumference which acts as an additional heat shield to protect against external heat. The only thing that might improve the appearance of your seemingly mundane stock barrel is the Agency Arms gold DLC coating which offers the deepest black color possible closely replicating the appearance of an OEM barrel. However this coating is much more durable than simply polishing the metal; it forces a harder and wear-resistant surface coating. The only reason you'd ever want to swap out your stock barrel is if you had a more exotic looking slide. However if you only want to change the color and not change anything else then a Glock 19 Mid Line Barrel is all you need. Specifications for Agency Arms Mid Line Match Grade Drop-In Barrel Fluted Glock 19: Manufacturer: Agency Arms Fabric/Material: 416R Stainless Steel Caliber: 9mm Luger Gun Make: Glock Gun Model: Glock 19 Barrel Length: 3.91 in Flutes: Yes Weight: 6.2 oz Included Accessories: Barrel Case Condition: New Features of Agency Arms Mid Line Match Grade Drop-In Barrel Fluted Glock 19: Twist: 1/10 Quality: 416R Stainless Steel Rifling: Pulled broached/ Saami Spec 9mm Rifling Fit: Glock 19 Gen 1-4 Compatible Caliber information machined on the rear of the lockup Identified as "919" Threading (Optional): 1/2 x 28 Thread protector (Price included with threading): Yes In matching finish Finish Options: Stainless Steel DLC (Diamond-Like Carbon Coating) Titanium Nitride (Gold) Barrel Length: Sits Flush with Slide (non-threaded only) Deep Crown (non-threaded only) Large Agency A machined on the Top of the lockup. Large AGENCY machined on the Port Side of the lockup. (7) Gear Flutes machined around the circumference of the barrel. Package Contents: Agency Arms Mid Line Match Grade Drop-In Barrel Fluted Glock 19 Barrel Case What firearm models does the manufacturer say Agency Arms Mid Line Match Grade Drop-In Barrel Fluted Glock 19 is compatible with? The manufacturer suggests that Agency Arms Mid Line Match Grade Drop-In Barrel Fluted Glock 19 is compatible with Glock 19Agency Arms 25G19-BML-SS: Mid Line Compatible With Glock 19 9mm 4.01 Stainless Steel