We weld a lot of 416 here.  Mostly to Inconels.  I try to stop it.  They keep throwing it in my face that they have been doing it for 30 years with "no problems".  Well, I have been here for 5 years and am working actively to document the hot cracking occurances.  Now at least in design reviews they usually listen and will substitute 410's.  We are part of GE, and the GE design standards ban welding of 416.  On designs where they use it they get a variance or "deviation".  It can be welded in some cases.  We have some details where we make hundreds and hundreds of parts with no problems.  But then, we are making tube welds and not fillet welds...