I usually keep my hunting setup with fixed bladed braodheads around 12-15 FOC. these seem to work best for my setup. How can you adjust for FOC? If you want a higher FOC, you would add a heavier tip, or wieght, or decrease the weight of your fletchings. If you want a lower FOC, you would do the opposite.
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"I do not Hunt animals to Kill them. I kill animals because I Hunt." Roger Rothhaar