Can you use a 165 Accu Bond to take one? Under the right circumstances I would think so
Uh... the 165gr Accubond out of a magnum cartridge is gonna bring a lot of pain. There's not gonna be many more "right" circumstances just by moving up in bullet weight.
Elk are certainly big and tough, but I've seen too many killed with 30-06s shooting 150gr cup and core bullets to give any doubt about the OP's load. My dad manages to find the right circumstances to kill elk every year with said load. Until I stepped up to 168gr TTSX in my 30-06 this last year, I did it every year
too with 150gr cup and core bullets.