She needs better penetration in a target like that. Step up to FMJ's in something heavy and zippy like a .44. Jumbo will only leak butter if hit in less than vital blubber.
This case calls for a rifle caliber, like 30-06 or better. 50 AE though, might be just barely adequate.
Trying to shoot a 600 lb. man would be like bringing down a bear or something.
What she needed was a harpoon.