Roskoe - the chart isn't 100% precise, but it's close enough to get in the ballpark.You're right,the chart doesn't account for the peep/nockpoint gap, however it ALSO doesn't account for the arrow slowing down downrange- which will offset what you're talking about, to a degree.

For my hunting setup, I'm coming in right around 350, andthat ballistics calculatorputs me +/- an inch or two.