You are probably underspined in my opinion. Pay no attention to Gold Tip's spine chart. It allows you to shoot a slightly weak arrow, which I do not believe is good when using broadheads. Also, if they have the older lok nocks, then I'd recommend replacing the nocks. They can be too tight and you'd still be able to turn them. Gold Tip quit offering the lok nocks because of the tendancy to overtighten them which causes the shaft to crack.