Shadow Systems Match Grade, 4.5 Threaded Barrel, Spiral Fluted, 9MM, Fits Shadow Systems MR/XR Models, Titanium Carbo-Nitride Finish, Bronze SG9C-02-03TSPL-BRZ Shadow Systems barrels feature minor improvements intended to create more consistent lockup without compromising reliability. The chambers are fully supported and can be fired with hot P ammo and lead bullets. The sample barrels that have survived 5 proof rounds so it is unlikely you will have issues with any mainstream" commercially available ammunition.