When I lay out my bows, I mark the center of the bow, tip to tip, then measure up 1 1/4 inches and that in my arrow shelf/top of handle, then I measure down 4 inches from that and that is the bottom of my handle. Sometimes when tunning and you get the string nocking point too high, it will have a reverse effect on arrow flight and the nock of the arrow will fly down ward and hit the shelf. Where did you start out at with the nocking point on your string? I would start at about 1/4 inch and see what happens.