This is my formula for carbon shafts:
FOC
ARROW length 29.5
shaft+feathers+nock wt 259 (Beman ICS Bowhunter 500)
separate insert weight? 30 (standard aluminum that comes with the ICS)
adapter weight? 100 (Steel from 3rivers)
point weight 130 (Zwickey Delta - been sharpened a few times so 130 instead of 135)
total arrow weight 519
balance length 21.25
FOC % 22.03
GPP
draw wt 46 (Kanati)
arrow wt 519
GPP 11.28
This combo will shoot through whitetails easily. It also kills the heck out of turkeys. :D
This year I'm going with Deltas on POC shafts...old school trad...
BTW: I mount my broadheads vertically as well. I also use the back of the head as a draw indicator.