okay went and tried this set up. 5575 arrow 32inc full length with 4 inch feathers, regular nock, 170 gr brass insert, 100 gr point. same set up as before but 5575. shot it thru paper and got bullet hole 2 x. with this arrow my foc is 18.75%. the arrow starts tilting off counter at 10inches. I tried computing my foc and it is above stated. should I try the arrow without the brass insert to improve my foc (i.e lower it)? I never messed with the foc so new with this too. I am going to shoot the 2 arrows at 20 yards and see how they perform, i.e my two 5575's I just got.