The subject of string stretch/ nocking point moving comes up all the time here. Anyone who has had or has this problem may benefit from little bit of advice. When you get a bow and have the draw length set right for yourself, take a pencil or some whiteout or anything that you chooseand mark the side of your cam where it passes through the limb. One mark on each side of the limb will work just fine. For two cam shooters you have two of them to do. This will ensure that you have a reference mark to tell if your string or cable is stretching and either effects your drawlength. These marks also come in handy when you change your rigging so that you can set your bow right back up to your drawlength. Hope this helps many fellows who would ask the question in the future.