What I did when I got my last new bow (at a local shop) I shot different weight arrows through the chrono until I found the one that gave me the most ke...I don't know if this is correct but I have had no problems doing it this way. I am fixing to have to do it again as I am waiting on a new bow.I will do it the same way. I am sure if this is wrong, someone will let us know as on this forum I hear the guys talking about momentum, I always thought I wanted the most ke I could get????