For my hunting arrows, with broadheads, that I don't expect to be shooting over 30 yards, I use 5" for stability. For target arrows, that I will be shooting out to 60 yards, with field points, I use 4" to cut down on wind drag. All of my arrows are bare shaft tuned to fly true out to at least 20 yards without feathers, so I can get by with very little feathers with field points, probably less than the 4" feathers that I use. I don't notice much effect from wind drag at short ranges under 30 yards, so I use the larger feathers to help keep the broadheads on course.