As much as I would love to say I started this thread to invoke brutal debate, in fact I did not. I started this thread because there is a handful or two of guys here that really know AR-15s ( I do not count myself among them incidentally) and I have read a few articles lately about using grease on very specific parts of the Bolt carrier and bolt as well as the mating surfaces on the upper receiver. Assumably we are not talking about grease on the gas rings, extractor, locking lugs or firing pin, but primarily the rails, sides of the gas key, cam channel and upper half of the cam pin. I would also assume cold weather would not be a condition one would use grease in.
And hey, if a fight breaks out that's just icing on the cake.
For the record I have always used SEAL 1 or bore solvent, followed by gun oil or CLP in the barrel and CLP everywhere else.