I' d recommend a large cutting mechanical.

I' ve had success with NAP Spitfires - 1 1/2" cut
and Rocket Sledgehammers - 3 1/2" cut.

...but, as mentioned, shot placement is more
important than the broadhead. It doesn' t matter
what BH you use if you don' t hit them in the
right place. They are really tough birds[>:].

Good luck hunting-
TB