RE: Formulas for IBO & AMO.
I've never concerned myself with IBO rating. I didn't worry about it when I shot compounds and I certainly don't worry about it with traditional bows. IBO shot at 5 gr/pdf? Give me a break.
For compounds, IBO used to be 70# @ 30" with a 350 gr arrow. Has it changed, or is it different for traditional gear?
Bill