Ammo- Hornady Superperformance popped primers on my 16CL barrel.
I found the 18ss barrel, heavy buffer, PRS stock and BattleComp brake world really well together.
The OBR is really a work of art, I think prettier than the MWS. The ability to have an MWS be a 16Cl lead slinger, a 18SS 308 and a 20in 6.5 gun all in one platform is pretty special.
Neither are bad choices. The best thing is running distant steel and not having to wait for the RO to know definitively that you got the hit.