Moving to Grendel for longer range competition. Only selling my .223 upper and keeping my lower to match up with a JP Grendel upper. The upper was built around a Black Hole Weaponry SS, 1:9, 16", 5 land polygonal barrel. Cerro forged receiver with milspec WIB bolt carier with MP bolt. Shoots sub MOA all day long with good commercial ammo and better with handloads. $450 plus shipping or trade toward Sig P938.