The charts will only get ya close, you have to try different shafts. What do you want to shoot, carbon, wood, aluminum.

I was in the same boat as you, what I did was saved some money and bought a Fletching vice, that way I didnt have to relie on any one else for arrows. Then I went to the Gander MT in my town and bought 3 shaftes in 3 different spines, 2117, 2020, 2216 and shot them all. It tock me a long time to figure out the best arrow and I switched back and forith a few times. I ended up going with the 2020s.

There is no way aroundit, you have to shoot different shafts. I cost money to startany thing new but once you get what you need things get more reasonable.

Good luck

Ow yah, I shoot a 45lb at 28 Bear Griz, the 2020s seem to stif for that, if that helps any.

I would say somthing around a 2019, but I am not sure.