Hi Bill, I love the laminated birch shafts. I have the 5/16 50-55 spine shafts. I shoot them out of three different longbows, 2 straight bows at #48 and #50 and one r/d bow at #42.My arrows at 28 3/4" with 145 STOS or field tips weigh between 580 and 600 grains.I haven't had to straighten them as they came in a bundle and were pretty straight.I just keep them in the bundle untill I am ready to use them.It is important to be sure the laminated grain is perpendiculer to the bow string when you put on your nocks.They shoot great , tune easily and give very good penetration. Hope this helps.Any more questions just ask. At this time I wouldn't use anything else. Bob