There is a lot involved with center of pressure, it's not a simple calculation since it is dynamic calculation. For example, the COP of a bullet will change as velocity changes, which is also true with arrows, but not enough to talk about since we are dealing with extremely slow velocities when it comes to ballistics. Your fletching is what shifts your COP rearward. So a higher or longer fletching will shift it back. A tapered shaft helps too because this will not only shift COG forward, but help move COP back during flight. Maybe I shouldn't use this as an example, but, the opposite of a tapered shaft would be a long range bullet where the ogive is extremely long, this creates in flight COP in front of COG, a very bad thing. So these have to be spun like crazy to over come the instability of the light weight front end and a heavy rear. With arrows, we don't have to worry about that, but tapering is a solution for flight shooting rather than increasing fletching height, along with its other benefits for flight shooting.
