Aero Precision M5 Barreled Uppers are changing the way you shoot large calibers out of a semi-automatic AR-10 platform. The AR-308 platform is not as plug and play as the AR-15 platform and can be a headache when building a gun from the ground up from different manufacturers. Solve that problem with this Aero Precision M5 Assembled Upper Receiver. This model features a 20” 416R stainless steel heavy barrel chambered in 6.5 Creedmoor for long range precision shooting and hunting. Comes with a low profile gas block and rifle length gas system for reliable function.