As I recall from days long ago, all bows were listed in 5lb increments, 40, 45, 50, 55 etc. When I went into an archery shop, I do not ever remember looking for bows with weights of other than the 45, 50 55 etc. When they were being made they were classified this way. But as they were being sanded to finished weight, weight varied slightly, depending on how much sanding was involved. So they labeled them in the 5 lb increments. Bear wrote actual weight on side of rest and covered with the plate material.