Just as a sidenote,I was visiting Eastons website yesterday (yeah im lazy and shoot alu and carbon arrows)and found a "kinetic energy calculator".
According to them a 550grain arrow at 170fps delivers 35.3 ft,lbs and isnt recommended to anything bigger than deer or antelope.
To get it up to the 42 ft.lbs they think is needed for elk boar and black bear you need to get it flying at close to 200fps.
Im no bowhunter ( its against the law where i live)but it looks like they cater more for whelie bows.
/Mikael