Taroman has it correct. The normal cold bluing solutions will sort of work but the result is not at all durable so rather quickly the barrel will look pretty bad. Now, the big question is the matter of the gas block, assuming it's an AR barrel. I don't know how thick Ceracoat is after it's fully cured but there may be a risk of not being able to get your gas block on the barrel if it's too thick.

BTW, I have a Shilen barrel on my 20 inch precision AR and when my eyes are cooperating I've managed consecutive 3 shot groups under 3/10 MOA.