dg3, the reason for this is because at 10ft your fletched arrows have stablized them selfs. where as a bare shaft has nothing to stablize it. try shooting clocer i like the 1 1/2 arrow thing or 3 ft. shooting this cloce will show what the arrow is doing right off the rest, make your adjustments and re shoot till your getting bullet holes then go to 10ft and shoot your bare shaft. i even go so far as to shoot a bare shaft at 10yds and 20yds to see if they will group same as my fletched arrows.
Ron