Electric angle grinder with a cut-off blade will take that off in a jiffy. Keep the hammer in water though, and make incremental cuts so you don't lose any of the existing temper.
But if it's really a throwing hawk you want why not seek out a inexpensive Cold Steel or other low budget jobbie that is specifically made for that purpose.
But if it's really a throwing hawk you want why not seek out a inexpensive Cold Steel or other low budget jobbie that is specifically made for that purpose.