Now, do I actually put it on the receiver threads, or on the barrel where it goes into the receiver, or both?
Also, I know the torque spec on the barrel nut is supposed to be something around 30 lb/ft (what exactly is it, please?), but what do I do if I get to that point and the nearest "notch" doesn't quite line up with the hole for the gas tube? Tighten it until it lines up, or loosen it?