For some reason I thought this was covered as a sticky somewhere on the forum but I can't find it now...

Cut down to the bare basics, the blades on a fixed broadhead can affect the flight of an arrow...It might be an inch at 25 yards or several inches...To tune the bow to the broadhead you move either the nocking point up or down or the rest up or down or right and left slightly...In doing so both field points and broadheads will group together...

Paper tuning will get you in the ballpark but broadhead tuning will help accuracy with specific broadheads...