I have always tried to follow Chuck Adams advice, and select an arrow- broad head combination that would weigh at least 7 grains per lb. of draw weight. For a bow set at 60 lb. the arrow- broad head would need to weigh at least 420 grains, which computes to a fairly heavy arrow . His reasoning is that although lighter, "knitting needle" type arrows fly faster, they also put more stress on a bow, and come closer to the stress of dry firing . I recently bought a used Matthews, and the guy had it tuned to shoot 85 grain broad heads, which would seem rather light for a bow set at 60 lb. Anyone else follow his advice, or have input? thanks