Just for the sake of doing so, I took the barrel off my ACR this evening. When reattaching, how much torque is required to ensure it's back properly? I torqued the barrel until I couldn't hear it ratchet anymore and checked alignment via the U mark on the gas plug in relation to the front BUIS. Once centered, I left it alone. Not sure now if I'll have to re-zero at the range but I'll find out soon enough.