Have recently purchased a BKII and really like the bow. I have a question for the experts on arrow flight. The bow is 70#, 29 inch draw lenth, string loop and release. Shooting gold tip hunters 3555 27.5 inch and 125 gr heads. According to their web site these are not underspined and the foc is ok. The broadheads hit about 8 inches left of where the field points hit. I've tried thunderheads, muzzy, and phantom fixed blades. The fixed blade heads plane fairly bad which is not surprising and the thunderhead and muzzy shoot the same. I don't think it is a tuning problem as the groups are good, the broadheads shoot left. Is this a common problem. I've never had a bow, that when tuned, didn't shoot broadheads and field points the same. Would it help to switch to a 100 grain head with these lighter arrows? Any comments would be appreciated.