What Straightarrow said.
IMO, when you're talking FOC values below 9%, you better be talking target arrows. Hunting arrows should be at least 9%, and the more exposed blade surface area on your broadheads, the higher it should be.
I know, there are some guys out there that get away with using ultra light broadheads, but there are some guys out there running around with rings in their noses and eyebrowsandbolts in their tongues too. I don't have to do something stupid just 'cuz they do.
I think one reason people have so many problems with broadhead accuracy and arrow flight is they go too light on FOC, trying to bump up their arrow speed or because they have the mistaken idea that heavier tips will cause their arrows to drop faster. With hunting arrows,losing stabilityandforgivenessfor a few extra fps or hoping for a little flatter longrange trajectory is never a good tradeoff, in my book. Like Straightarrow said, when you usea rangefinder, trajectory and speed practically becomenon-issues.