I've used these shafts to build some good arrows for indoor archery and 3D. With a little added weight, leaving the shaft 31-32 inches long, I get a good spine match to my 50 lb Mathews Title-38 bow. If you use higher draw weight, cut the shaft shorter and use lighter points. You should be able to get a good spine match with bows up to 65 lb. These are straight enough to consistently hit the 11 ring if I do my part. A great price, because these arrows are a discontinued model from Carbon Express. Still one of the best carbon shafts ever made. I've bought two dozen from this seller so far and all have been shipped promptly and packaged well.