just a word of advise but dont always go off what a manufacture chart says, they leave a lot to be desired.
if you have not tried pinwheel software then you should give it a whirl. will get you right where you need to be.
I shoot harvest time arrows and according to their chart i should shoot a 400 fine but with todays bows and what not i found out that a 350 spine was actually much better and the 400 was actually a bit underspine. some may never see a difference but the spine issue may be the cause of some having issues with tuning broadheads vs field points.