Rick,

I see that you are back in country again! As far as FOC there are many opinions on it, but it is not as critical as some think. I like to stay about 10-12% on all of my arrows, but will shoot lighter if I am trying to achieve a lighter arrow. As I mentioned above there is an "effective FOC" which is higher than the computed, this is generated by the parasite drag. As the speed of the arrow is increased the drag increases drastically. Depending on the type of fletching you are shooting the drag will vary, with feathers it probably quadruples for a given increase in speed, giving you added stabilization. From flying you know if your CG is too far forward the aircraft nose is hard to lift, with an arrow it causes the arrow to want to drop out quicker with extra nose down flight characteristics (extra drag). If you have a light FOC, with a properly spined arrow and a tuned bow you will see very little ill effect with fieldpoints. Shooting fixed broadheads is another story with the canard the blades provide on the front of the arrow creating some lift. If the FOC(CG) is too light it may cause the arrow to tip stall which maybe seen as porposing. As I stated I have been as light as 8% on my broadheads and they grouped right with my fieldpoints. So if your arrows are grouping well and it ain't broke, don't worry about it. If you have an old arrow without a tip shoot it 60-80 yds, you will find that it flies pretty well in most cases. This is because of the stabilization of the fletching which increases the effective FOC. Steve Jackson can give you more on effective FOC, but what I gave you is the long and short of it the way I understand it.

Some of the trad. shooters will use very high FOC's which tends to drive the arrow, but they tend not to shoot out very far, 20-25yds in most of their shooting. A traditional field archer will generally have their FOC close to the 10-12% range in most cases to maintain arrow flight. Reaching out to 60-80 yards for them is sometimes a problem depending on the bow.

For 3-D a FOC anywhere from 8-12% would be plenty fine, but as I said I have shot at 6% before and it worked out fine.

Edited by - FLHunter on 01/05/2002 10:51:17

Edited by - FLHunter on 01/05/2002 10:53:03