I also heard Stainless holds up better againts rust, blue steel needs more care.
Stainless steel requires less maintenance, but I've got a K-38 Combat Masterpiece from 1974. Back then SW used the real blueing process, and the blue steel looks like its a foot deep. Probably the best looking gun in the accumulation. Still new in the box, never fired. Its my Vietnam tribute gun, same one I carried as a Security Policeman in the Air Force from 1969-1971.
Blue Steel is definitely stronger than stainless. Le Tigre and Ferrari are too. However, nothing compares to the strength of 'Blue Steel' to a non-ambi-turner.
They have different properties. Bluing on steel is a surface treatment that helps inhibit rust, but doesn't prevent it. It will wear off with use over time, but can be redone. Stainless steel refers to a particular type of steel alloy, usually incorporating nickel and chromium, that is highly resistant to rust on its own, so doesn't need a surface treatment. Because the steel itself is what is rust resistant, that property can't wear off. All other things held equal, the carbon steel that bluing is typically applied to tends to be slightly more rigid and brittle than stainless steel. It may hold an edge better than stainless. In most applications, those differences are small enough not to matter for practical purposes. For example, both knives and guns are made with blued steel and stainless steel. Which a person gets is usually a matter of preference (unless you're, say, a professional restaurant chef whose knives have to hold a fine edge through constant hard use).
