The optimal FOC for hunting is from 8% to 12%. The higher the FOC the more the arrow will want to nose dive which increases stability but also decreases effectice range becuase the arrow arcs alot more at longer didtances.
Sorry, but I have to disagree. I think the 8-12%, and similar range recommendations, came from the pre-carbon days of heavier arrows. Getting a FOC higher than that was very difficult without having an arrow that was so heavy you couldn't shoot past 20 yards. I know many superb hunters who use carbon arrows with FOCs in the 25-30% range and haven no problems. Myself, I have several dozen arrows of different brands, and they range from 19% - 25% FOC and they fly incredibly well and are superb for what I want and how I hunt.
What is optimum varies with a hunter's goals. If you're shooting little animals at 50 yards, then low FOC, lighter arrows may be what you want. If you're hunting water buffalo at 15 yards, the super high FOC arrows are definitely the ticket. A narrow optimal range does not exist.
High FOC arrows do not make your arrows nose dive. That is a myth. They simply weight more and heavier arrows travel slower, allowing gravity more time to work it's magic.