I' ve recently made the switch from aluminum to cedars. I' m shooting a 60" longbow @ 51#' s. Arrows are spined 65-70# and are cut to 28.5" with 125g heads. The heavier spine was the bowyer' s recommendation and he and the arrow builder watched as I shot several arrows of different spine before I bought these, but I was shooting at any empty bale with no dot and my form was probably not what it is now. They seem to leave the bow cleanly enough, but the problem is I impact left of aimpoint consistently( usually 3-4" left @ 15 yards and 6-7" out past 20). I thought maybe I was pulling my bow arm and it just needed strengthening because I converted to traditional only about 6 months ago, but I' m beginning to wonder if I may be overspined becuase I switched back to the 2213' s @ 28" arrows that I learned on and the problem goes away. They are probably 200 grains lighter and I' m guessing borderline underspined. Help, hunting season approacheth!