FOC question...

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FOC question...

Postby Gamikatsu » Sat Dec 03, 2011 5:19 pm

ok... so in a few short words, can someone give me the plain english idea behind FOC and how it effects accuracy? my arrows i calculated at 13.6... measuring from end of nock, to tip of broadhead... using rage broadheads... 22" total length, 14" from nock balance point.
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Re: FOC question...

Postby SPITFIRE » Sat Dec 03, 2011 5:41 pm

Think of a dart. The head is heavey so it pulls the tail along. Arrow is the same, heavey in the front and the tail steers. If it was heavey in the rear the tail would steer. Not good JMO :)
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Re: FOC question...

Postby Gamikatsu » Sat Dec 03, 2011 6:07 pm

mk... do you measure FOC by measuring just arrow, or arrow + tip? i see theirs two versions? full arrow+ tip gets me 13.6% if i do the AMO version, i get 18.6% or something like that....

same arrow/tip combo... two different numbers... of course it has to be difficult.
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Re: FOC question...

Postby wabi » Sat Dec 03, 2011 6:10 pm

If you don't have 218% FOC you're wasting your time & money buying a deer tag & hunting. :shock:

At least that's what a lot of people who sell heavy broadheads and brass inserts want you to believe. :wink:

For me, I'll just keep quiet from here out on this subject and keep hunting with my same old aluminum arrows with about 10% FOC that I've never had a problem shooting very tight groups and killing deer with. :lol:

I'm NOT saying more FOC is bad, just saying way too much importance is placed on increasing it when (and if) the setup you happen to be using works just fine. If you have accuracy problem it's fine to experiment with increasing FOC, but if you're not having problems why waste time & money fixing something that isn't broken?
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Re: FOC question...

Postby masboy » Sat Dec 03, 2011 6:13 pm

for me a heavy foc of 17- 20 gives me a much more forgiving set up.I shoot just about as well for groups with my lite foc 360 gr arrows on my best days. but every day I shoot good with a heavy foc .
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Re: FOC question...

Postby ElmerFudd » Sat Dec 03, 2011 6:53 pm

Firebolts and a 125 grain field point or broadhead works out to 50yds for me. I agree with wabi. Shoot it and if it works--it ain't broke. Just remember not to shoot at the same spot twice without first removing the previously fired arrows from the target. :D 50 yds was only accuracy testing I would not shoot at a deer that far. When first testing my Axiom four different people shot from a rested position, me, my Grandson, Grandsons friend, and my Son In Law. From 40 yds we each put an arrow very nearly into the same hole. My Grandsons friend had never in his life fired anything, not even an air rifle!!!!
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Re: FOC question...

Postby Mark Rainbolt » Sat Dec 03, 2011 7:44 pm

??? What the heck is FOC and how do you calcuate it to your arrow???
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Re: FOC question...

Postby bob1961 » Sat Dec 03, 2011 8:18 pm

here is a good site to figure your FOC without the measurement method....

http://cacciaebalestra.altervista.org/INGLESE/Main0.html

it is under tables on the left :wink: you can adjust weights of stuff to see what FOC you get with what....oh yeah my FOC is 21.6% :wink: .......bob

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Re: FOC question...

Postby awshucks » Sun Dec 04, 2011 1:45 pm

FOC =Percentage of total weight in front of center.

On 20" arrow, each inch between middle [10"]is 5%, i.e. 100% divided by 20" = 5%

On the 22" arrows, 100% divided by 22" = 4.5% I calculate that FOC as 3" X 4.5% =13.5%

i calculated at 13.6... measuring from end of nock, to tip of broadhead... using rage broadheads... 22" total length, 14" from nock balance point.


Here's the hillbilly method: Mark center of arrow, mark balance point, multiply the diff by appropriate per cent, and wala! Friggin close enough, lol.

Imho, higher FOC w/ fixed blade bheads will cover some arrow probs.

Wabi has no doubt well set up arrows, or may be shooting mechanicals, either of which scenarios will easily tolerate a lower FOC.
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Re: FOC question...

Postby flightattendant100 » Mon Dec 05, 2011 6:21 am

Mark Rainbolt wrote:??? What the heck is FOC and how do you calcuate it to your arrow???
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I thought they were trying to talk Texan,ie. "Where the FOC did I put my beer",or "How the FOC did I miss that shot". All this time it was about ARROWS!
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Re: FOC question...

Postby Dash » Mon Dec 05, 2011 9:04 am

I've seen a few very different figures quoted for ideal FOC over time. Instead of worrying about the numbers, just get out there and try a few different weight tips to see what works best for you. Under 30m it didn't make too much difference for me what weight I used up front (All groups looked good). But at 40-55m it will be easier to compare the difference and see whats best for your setup. Good luck
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Re: FOC question...

Postby sumner4991 » Mon Dec 05, 2011 10:01 am

FOC will not fix a bad shooting bow/arrow combination . . .it may help a little, but, it is not a fix.

FOC is something for the anal archer.

The front end of the arrow needs to be heavier than the backend of the arrow . . .anytime you screw on a tip, you will be good to go.

Consistancy is the key to accuracy. Every component needs to weigh the same. Exactly, the same? Not really, but, that depends on just how far you are shooting and just how tight you want your groups.

Too much FOC and your arrows will "nose dive" at longer ranges. How far out this "nose dive" takes place and its severity depends on the speed of the bow and the weight of the arrow.

Too little FOC and your arrow will float and be easily "pushed" by any crosswinds. They will still shoot pretty accurate. I suppose if somebody has an arrow that is heavy enough to shoot without a tip, then they can test this theory and let us know the results. :shock:

Most arrow combos have sufficient FOC.

You need to weight your arrow according to the game you are hunting for proper penetration. If you have proper penetration, then your FOC will be just fine.
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