Rifling in an AR barrel is one of the most important features for shooting accurately. Somehow this hasn't been the focus on shorter barrels for the pistol market- until now. Fortis manufacturing is using a process that utilizes their lone rifling technology. This process utilizes a single point cutting technique for greater precision and ultimately, much better accuracy. The concentricity to the bore is unmatched and it shows in the shooting experience. Run it harder, faster and more accurately with the Fortis Glock line of barrels. Fits the G19 Gen 1-5 and also fits the 19X. FeaturesUltra precise concentricity to the boreLone Rifling technology yields identical grooves11deg Target CrownComes with threaded barrel protector (protector is black nitride)Compatible with Glock 1-5 as well as Glock X