Carbon Tech Arrows.
I am really impressed with the accuracy of these shafts out of my XLR. I also shoot ACCs and ACC Pro Hunters, which are supposed to be the best as far as accuracy and spine, but I almost always get the best groups from the CT arrrows. I usually shoot three arrow groups in my basement at 20 yards and the CT are almost always touching each other. My ACC groups are usually within 1"-1.5", but don't touch as often as the CT arrows. Any explanations to this? They also seem to be very tough shafts. Does anyone else shoot these arrows?