Does any one know more or less what is the steel composition of air rifle barrels?
Can they be blued, or are they just painted? You need a fairly high carbon steel for the bluing to be done safely.
That sounds like the question: how long is a piece of string? I am sure different manufacturers use different steels, but you can blue most steels (obviously not stainless steels)
You can blue carbon steels but also normal mild steel, I have found it just takes a little longer in the solution for low carbon steels, but they then blue very nicely.