This isn't totally true.It is true that the arrows spine is measured on a spine scale but that isn't the end.

We need to know the DYNAMIC spine of an arrow to know how it will perform,or should perform out of a particular setup.Everything from using a d-loop to having an overdraw and point weight affects the dynamic spine.


There must be a formula for that becausealot of the charts ask for point weight but the arrow programs ask for all these details,I am not aware of what kind of formula or if they just figure some sort of % spine increase for fingers verses using a release with a d-loop.


Arrowmike is absolutely correct about arrow quality playing a factor.