Question: what is the difference in arrow sizes?
Answer: The same Easton arrow comes in a variety of stiffness: the lower the number, the stiffer the arrow. For example, a 330 arrow is stiffer than a 500 spine arrow. ... The number of inches the arrow deflects or bends X 1000 due to the weight is the spine size or measurement of an arrow. So, a 500 arrow bends .