What chambers are used in DPMS AR15 barrels?
To determine the chamber of your DPMS barrel, look to the underside of the barrel forward of the gas block/front sight base for the chamber stamp. This stamp will give your rifle’s actual chambering along with the twist rate of the barrel. DPMS currently produces barrels chambered in .204 Ruget, .223 Rem, 5.56x45mm, 6.8 SPC II, 7.62x39mm, .243 Win, .260 Rem, .308 Win, .338 Fed and 6.5 Creedmoor. The 300 SAUM has been discontinued.