Thanks for the info. I am currently in the market for a 4-inched 586. They do seem more rare than 686s right now. I even see more good condition 4-inched Blued King Cobras than 586s.
I have always thought that the difference was just Blued versus Stainless. Is this not true? When you search on Gunbroker, you get Stainless and Nickled(?) that are being sold as 586s.