I have a Drenalin LD, the limbs are turned down as tight as they will go. My draw length is 31in. Right now I shoot beman MFX 400gr. arrows with 100gr. broadheads, the set up is good. However when I looked at the beman arrow chart it recommended 340gr. arrows is there anything to gain from changing to a lighter arrow, and could I damage my bow. Just looking for some input. Thanks