Never hunted elk ,but what I have found on Hogs is that a lighter bow properly tuned and drawn FULLY without struggle and shot accurately will penetrate as good if not better one someone is struggling with . I would rather have another inch of draw than 5 pounds drawn shorter
The key is a finely tuned bow/arrow combo with a SHARP 2 blade head in the vitals .
I know some will disagree with my statements , but that is ok . This is my opinion based on experience and cannot be changed very easily .
Again I have NEVER hunted Elk .
Good luck in your quest !