the question comes up occaisonally, about interchangability.
blue and stainless are for the most part interchangable, some will work better or worse depending on the frame; gen I, II, III or even G2. split lugs easy open frames so on. the greatest concern is to watch out for Armour Alloy, this was a coated system that really only worked well together. fortunately for the swapping community this system wasn't long lived. I have heard that an AA bbl can be factory refinished to work on regular frames. just a side note bbls in question will be marked AA for Armour Alloy. this was a corrosion resistant coating to combat inclement weather..... because as we all know stainless steel can still rust as it is steel and contains (Fe) Iron. stainless is simply less likely to do so therefore called stain-LESS, due primarily to the inclusion of (Cr) Chromium.