Unknown location, date and unknown person... Sykes Reef (Australia) , 1963ish, Wally Gibbins. 11 foot tiger shark taken with a 10 gauge powered spear. By the wound on the shark, the gentleman was underwater and facing the critter before he took it with a ( possible 12 gauge) bang-stick.
And not a small shark either!
Thanks to Bill Baldwin for filling the blanks.