Perhaps this may only be for my bows arrows and shooting, but I have wood arrows that will shoot accurate and fly straight out of four different weight bows. Those tapered carbons do not fly for the bow I ordered them for, but they do fly out of another. I have aluminum arrows,1918s that will fly out of a 52 right hand bow but will not fly as well out of a left hand bow of the same make and poundage, it prefers 1818s with a different weight head, where as the wood arrows will fly perfect out of both bows. It seems that my wood arrows may be forgiving of harsh releases more so than the carbons out of the bow they like, while the carbons and aluminums seemed to have no forgiveness of soft releases. I am sure others results will vary, but insisting that my arrows are always going be 27" bop for a draw check, I am self limiting my options for spines. I needed a sky hook to get those uncut target Bemans out of my back quiver, glad I found someone that could shoot them for 3D.