FOC Measurement

[nchunterkw]

How do you measure FOC, and what % are you looking for?
This link describes 2 methods.

http://archeryreport.com/calculators.html

I am using method 1. Seems to me the arrow will flex at impact and not the BH.
Haven't compared the two. Probably should have.

[awshucks]

I'd read of a simple method along time ago, forgot which forum it was on. You mark center of length of arrow, mark balance point. Measure diff in inches, then figure 5% per inch on 20" shafts, 4.5% on 22" ones.

It will put you real close to what the tables come up w/. I've come to consider FOC as low [8-10%] med [12-15%] and high [18+%]

Since we share a lot of info here, I had my eyes opened [forcibally, lol] by Boo this trip. I've been a higher FOC fan for quite a while. He had me shoot one of his arrows, not sure enough of make to post it, but it wasn't Firebolt or Gt, had alum insert and a 1" Slick that still had .010" run out. It also was fletched w/ 2" Blazers via the new[er] AZ-EZ Crossbolt for short vanes, tons of helical. Hit the bull at 30 yds.

[fuzzy]

...

[taz3]

With firebolts and 150 grain target points FOC is only 13%. I expected way more FOC with Firebolts.

[gerald strine]

http://www.stickemarchery.com/stickemca ... ators.aspx

This link is a very simple way to get your f.o.c use the f.o.c tab at top of page and have a ruler handy.

[awshucks]

Back in my anal days, I did quite a bit of experimenting w/ FOC. My tools were 100/125 gr field tips and lengths of 8-32 threaded rod cut from 6" lengths. I could screw pieces of it in either back of insert or nock.

It weighs about 25 gr per inch. While it affected poi, not so on group size.

YMMV [your mileage may vary]

[Boo]

If you arrows shoot well don't stress about the numbers. I've never measured FOC and don't want to either.