I have a 45#-60# FC400 and I'm working my way up to 60 pounds. I'm shooting 100 grain tips and 27" draw length. I am shooting GT Velocity Hunters with a 400 spine. The arrow shaft is 25.5" (26" with nock).
After looking at the charts I think I may over spined and should have gone with 500s instead. When I bought the arrows I didn't know what the length would be and went with a WAG.
What does your fancy program say I should use?