for a bow fully setup for hunting and an "average" shooter you generally loose 30-40fps off of IBO. thats "average" arrow weight, draw weight, legnth and string setups...sometimes more sometimes less...you shoot heavy arrows on a short draw and like a longer arrow and light draw weight, your going to loose more than the guy that likes a light arrow, as short as he can get them and shooting a maxed out bow...

30-40fps is usually pretty ballpark for a hunting setup though...