I am using 4 inch killer vanes, no wraps, not sure what sort of nock and no uni bushings. Icould shorten my arrows to 26 inches safely enough and try blazers but my calculations still say my F.O.C would be just under 10%. My arrows are rated with spine stiffness of 0.340 and 9.5 grains per inch. Do you think i might be better off going to the ST AXIS 500's that are only 8.1 grains per inch and a spine stiffness of 0.500? I just dont want to under spine my arrows and the nearest proshop is over 3 hrs away. Any suggestions?