I have a bear Kodiak Hunter #55 from 1970-72... I've been shooting a lot of arrows with it lately and the string just broke while firing an arrow. I have only had the string for less than a year and don't understand why it broke now. However, I want to go get another string and accessorize this bow for hunting. It has Amo - 60" listed on it and I'm not sure what this means. Anyways I need to get a new string and I want to maximize the most power I can get from this bow, should I concentrate on light and fast arrows for more kinetic energy or more mass for greater momentum? And does different string lengths affect the power of the bow? please all advise welcomed.