calculate my foc!!!!
i' m shooting a martin panther with 70#. My arrow is 27.25" from bottom of knock grove to end of shaft ( where i cut it). I' m shooting 3 4" flexi-fletch vanes on beman ICS camo hunter plus 500 (7.9gpi). The insert weight is 23 gr and knock weight is 13 grain. I' m either going to shoot 85 gr spitfires or 75gr jak hammers. Please calculate my FOC for those 2 broadheads and would you also do it using beman 400' s (9.1gpi) instead of the 500' s? Any info would be appreciated!!