I have found bore sighters to be quite valuable for evaluating bedding. Install and note cross hair coordinates. Without removing or touching such, loosen all screws and check for movement. If anything shifts at all, one has some bedding issues affecting his receiver. One can do the same exercise in reverse starting with his uninstalled barreled action. Assemble and tighten screws and again check for any shifts.
When I bed a rifle, I prop everything up, put in my compounds, and sit the barreled action in the stock with no screws installed what so ever and let things cure. When I subsequently cinch everything down, there are no shifts at all.
