DPMS sells some plain carbon tubes along with Clark, the DPMS are cheaper.
Need a receiver jig, vise, torque wrench, barrel nut tool, tools to take the sight and gas block off and reinstall.
The tube barrel nut screws on tighten to 38lbs min then to align the next hole, glue the tube on and reinstall the gas block and muzzle device.
hi perf barrels and bolts
The Nextgen of 308 rifles