Well, I've never shot an elk with a bow...so take this for what it's worth. I've shot numerous whitetail with a bow. Mechanicals and fixed. Tuning is a no brainer between most mechanicals and field points. When mechanicals first came out I tried some, don't even remember the brand. It had a long point that pushed back on contact, into the body of the broadhead, and deployed the blades. Not a very good design. Well I shot a deer broadside/double lung and never deployed. Fully pass through and the deer fell over about 50 yds away. I did see the deer fall over, and not a great blood trail. That arrow basically acted like a field point. My point is I believe that it really doesn't matter all that much mech or fixed as long as the shot is good. Now a marginal shot is a different story. IMO as long as the broadhead can pass through hide and ribs maintaining most of it's integrity you'll be good to go with a well placed arrow.