If I remember right 5shot did a fps test and it was about 6fps loss vs. a quicktune. Not much in my book, nor in that of a dead deer. Anyway, on my old style WB I put the arrow on the nock and pushed it forward then marked where each vane would hit the bristles. I then used one of those little scissors for trimming nose hair (not that I need one) and I trimmed about an 1/8 toa 1/4 inch from center in each of those locations.