I had been putting performance recurve in and just changed it to recurve it is pretty close at this setting within 5 lbs.   Should get you close enough to do some bare shaft testing.

Good stuff,  I will have been putting performance recurve in as well.

I bare shafted my 56" PSA III before I knew of Stu's spine calculator. WHen I enter the data for the arrow I shoot the tool proves to be almost right on.

I think the best benefit of the Stu's calculator is that once I know what dynamic spine flys from any given bow, I can use his tool to change shafts and when the new shaft matches the known good shaft things pretty much fall into place.

I have found that Stu's Dynamic Spine Calculator was very accurate for my widow.  I have also used the calculator for two of my buddies who also shoot widows and again the results are very close.  It should give you a good starting point.

These are my observations and experiences,as always ... your mileage may vary.


Freeze

P.S.
I am now in the process of tuning a Morrison Mini-14 ILF with W&W INNO Power limbs, and the calculator is WAY off from my bare shaft observation.  This may be due to the adjustment and variability of pre-load with ILF risers.