foc has to do with the balance of the arrow...what does mech,or fixed blade heads have to do with that?Also you CAN have a 540gr arrow with an 8% foc....You can have a 350gr arrow with 14% foc...7-15% is the accepted range with 9-10% being ideal.Your arrow is only about 377gr.It shouldn't be dropping off @25yds(I'm using one pin from 0-40yds with field tips,my arrow weighs the same as yours,but I'm not sure of how fast your bow is going)..The feathers are the reason why your foc is high,they are very light.It is still in acceptable range,but it is a hair high.So you can balance it out by dropping your tip.An 85gr tip will put you with an 11.1% foc,weighing in at 362gr.75gr tip will give you an arrow weight of 352 gr,andgive you a 10.1% foc,and is what I would recommend.OOps...what poundage are you shooting?352would bescraping bottom for a 70# bow.In that case I would go back to vanes,and keep your current head.That would put you at 394gr,and an foc of 10.1%.AND WOULD GIVE YOU A PERFECT BALANCE OF SPEED,AND ENERGY.Rocky mountain has a great 75gr head.It is called the Premier..it's a fixed blade head.Wasp has a variety of 75gr heads also..Hope I helped.