FOC is something that has been talked a lot about over the past few years,
and it is now becoming a marketing tool for manufacturers. Built-in Weight
Forward is a phrase that comes to mind. FOC is the percentage measurement
of the balance point of the arrow forward of the exact middle. Here is how
you figure it out. Measure the arrow from the very front of the point to the
very back of the nock. Divide that distance in half and make a mark on your
arrow - I use a silver Sharpie. Now balance the arrow on your finger and make
another mark at the balance point. Measure the distance between the two
marks. Now divide the distance between center and balance point by the halflength. Your equation should look something like this: (distance from balance
point to center point) / (half total length of arrow). If your arrow is 30.5 inches
from tip to nock, your center point should be marked at 15.25 inches. If your
balance point is 2.5 inches forward of your center, your equation will look like
this: 2.5 / 15.25 = 0.16393. If you multiply that number by 100 you'll have your
percentage Front of Center, in this case 16.4%. I have heard that anywhere from
11 - 18% is proper FOC, but there does not seem to be a consensus about what
percentage gives an arrow the best flight. Every expert in the industry seems
to have a different opinion about FOC, and even how to measure FOC. While
this should definitely not sway your decision to purchase or pass on an arrow,
it is something that you should at least give some thought to. Just remember
that if you want to shoot a heavier GPI arrow, you'll need more weight on the
front end to maintain your FOC.
With all of that in mind, how should you select your next arrow? Let's go back to
that initial question of "what are you going to be using it for?" If your answer is