While there is no question that the barrel shank fractured at the first thread, to characterize this as "Blew up" is exaggeration at best. So far as burns to your hands as a result, there is no reason for this happening any more with this event than when normally shooting any revolver. Again, somewhat of an exaggeration. Why?
There are several other things that cause curiosity. You say you received the gun and just put it away for several years? Where/when/why in that period of time did you polish the gun and paint the front sight of a gun you seem to have had little interest in?
Is there a particular reason you removed the stocks before taking the pictures? It fails logic to understand why this would have been done.