What effect does 25% FOC have on my arrow flight?

[miket]

This past summer I switched to Quikspin speed hunter vanes and they shot well so I never checked my FOC. ( I was using regular Quikspins) I just checked my arrow FOC and it is 25%! I have always heard that it should be around 8-15%. My arrow flight looks great( I practice at 60yds and usually get under 8" groups-better on good days) and haven't had any problems, but I was thinking about cutting an inch or so off my arrows but don't want to make the FOC problem worse. What effect does this extreme FOC have on arrow flight, and will shortening the arrow increase or decrease the FOC?

[Bisch]

Extreme FOC comes in at number three. Extreme FOC is
Study-defined as 19% or greater FOC, measured using the AMO
Standard method. (The AMO Standard Formula is presented in the
Prologue to the 2007 Updates.) First notable FOC gains are
manifest at that level. Between 12% and 19% is Study-defined
as 'High FOC'. At or below 12% is defined as 'Normal FOC'.
© 2007, Dr. Ed Ashby
All Rights Reserved
3
Until completion of light-draw testing Extreme FOC's
effect could not be accurately placed. In addition to its own
effect, Extreme FOC does more than any other defined feature
except flight-quality to maximize the effect other factors
offer.
All Extreme FOC tests show (or, as with the barrier and
measurement constrained 82# bow; imply) very, very high
penetration gain. This effect can now be quantified; at least
for high-performance arrows having most other penetrationenhancing
features. It ranges from approximately 40% to
upwards of 60%.

This is straight out of a report done by Ashby. I don't think extreme front of center can hurt you. According to him it is nothing but good.

I hope this helps,

Bisch

[EarleyBird]

If you are satisfied with the performance of your current setup, then it really doesn't matter. I know it's hard not to keep tweaking, though. I currently shoot Easton Axis arrows at 27" w/ either 125gr Snuffers or 100gr Montecs. With the 125gr Snuffers my FOC is over 12% and I'm good to about 20 yards with only one pin. With the 100gr Montecs my FOC is (I think) under/around 10 and I'm good to nearly 30 yards. So you can see how significant a small change in FOC makes in my setup. Alot of it also has to do with speed. My rig w/ the 100gr Montecs is shooting in the 260's. When I shoot my same arrows through a faster bow I get a little more range. Shortening your arrow shaft length will increase spine and therefore help stabilize an arrow that has a high FOC. I like the heavier BH's for penetration, but like the lighter Montecs for range.

But again, if what you have now is working, I would leave it alone.

[Mike D]

I gotta know, how did you get 25% FOC?

You ahootin 250 grain broadheads or something?

[miket]

Sounds like yall are right about leaving it alone. I never had a problem till I checked it! Mike, 30.5 long GT55/75 100gr FPoint or Rage and Quickspin Speed Hunters. When I was using regular quickspins (full length ) my FOC was about 15% if I remember right. The Quikspin speedhunters are about half the weight as the regular Quickspins.