# Building heavy FOC arrows for long distance?



## dwagoner (Sep 27, 2007)

how heavy you talking??? over 15% ???


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## Macker (Mar 22, 2007)

i have some victory hv 300's with 175 grain tips and they are at 22% foc. you have to go stiff on the spine in order to put a heavy tip on the arrow....feathers and no wrap on the back....helps the foc a lot.


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## amp713 (Jul 4, 2010)

Not really a certain weight or %. Just looking for guys who could reach out and touch something, I practice out to 90 and have tagged small game at 80 with just cheap off the shelf carbon arrows and have started to build my own... Just looking to hear what others are doing....


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## dwagoner (Sep 27, 2007)

I dont think FOC is the key to longer range shooting but more the weight and how it carries more momentum at those long ranges. I shoot long distance also but i bet im only around 12% myself. Im more worried about total arrow weight vs foc. my arrows drill BHs at 80 just like points so im more than happy. I think 15% is more than adequate depending on total arrow weight.


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## Hoytalpha35 (Apr 5, 2011)

I'm just starting to play with getting my FOC higher. My 3d arrows were around 11%. Now they are about 13.4% with a few changes. It's subjective, but I like how they are flying. For my hunting arrows I'm going to experiment with an arrow that'll be over around 14.5%.


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## rsb_924 (Mar 11, 2006)

amp713 said:


> Anybody here make arrows with a way heavy FOC for long range (80+) yard shots? Just looking to see whateveryone else does in this situation....



here's my 2 cents and yes i have Ben playing around with high FOC and i only use the high FOC on my traditional equipment. it seams that my 11% FOC on my compound works so i will leave that one alone for now. any-who here goes.

Arrow FOC (front of center / or sometimes called forward of center) is an important concept that all archers should understand. Whether bowhunting, target shooting, 3d shooting, the FOC of an arrow will affect the flight of the arrow. FOC becomes especially important the further downrange the target is, and also if a broad head (most notably a fixed blade broad head) is used. The basic definition of FOC is the percent difference between the physical midpoint of the arrow and the center of gravity (balance point) of the arrow as compared to the total length.
For penetration purposes, the opposite phenomenon occurs. A larger FOC will prevent and arrow from flexing as much when coming into contact with the intended target. Hunters will want a higher FOC so that as the broad head enters the game, the distance from the front of the arrow to the center of gravity is lower, making it more difficult for the arrow to flex. Any flex or deflection of the shaft upon entry means that energy is being lost somewhere other than directly along the center of the shaft, lessening the overall penetration. A larger FOC is necessary for shooting long distances where crosswinds tend to have a large effect on arrow flight. The same applies to shooting broad heads over field points because the larger surface area of a broad head is more greatly affected by launch imperfections as well as crosswinds. Broad heads tend to steer an arrow which can often have a negative affect that the fletchings must overcome.
There are two main ways of calculating FOC. Both use similar formulas; the difference being that one takes into account the length of the point and insert while the other does not.
When comparing FOC values, it is important that both values be calculated with the same formula. The second method will generally result in a lower FOC value.
Recommended values for FOC(using the AMO method)vary depending on the application, target arrows (field points) should generally be in the 8-11% range and broad head tipped arrows in the 10-15% range. FITA and longer distance shooters will often go for a 12%+ FOC, even though they are using field points, because of the long distances involved. Some traditional hunters have used FOCs of over 30% because with the right setup it can enhance penetration on animals. 

with that being said i have tryed an FOC as high as 28%


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## amp713 (Jul 4, 2010)

My total arrow weight is pretty good if not a lil on the heavy side for me, Im not sure what my FOC or final weight are the arrows i have just barely built but im sure they are heavy. I havent shot to far out yet so we will see what happens there.

I was hoping to aim for 11-13 so both of you two are right there, which is kinda what i was hoping to hear!

Rsb-I knew some of those facts and that was the reason i wanted to try them but there was a lil info in there that was new or revised so thanks for sharing all of that. How did your 28% foc's shoot? and how were you getting them that high? just weighted inserts? or were you doing a larger broadhead too?


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## grantmac (May 31, 2007)

Rather than a heavy point, go with a lighter shaft. You get the benefits of FOC without loosing trajectory.

-Grant


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## amp713 (Jul 4, 2010)

I personally dont want to go to a larger BH, in fact id even like to shoot a 75 grain head or somehting like that with a bigger insert. The heavier BH's are just made slightly bigger which adds slightly more drag in my book. So why not go smaller with more insert weight.

Also the shaft idea is a good one but i could see that being bad too, losing K.E. and momentum just to gain FOC is not the way i would want to go BUT if i was just trying to gain a small percentage and it didnt cost much for weight i could see going that route. I personally just change the arrow length versus the shaft, you gotta play with it but you can get away with it if you have the time. You can go short as long as your BH clears, and an inch or two out front is really not that bad.


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## Hoytalpha35 (Apr 5, 2011)

Go to Goldtip. They have a calculator that you can build arrows, figure out arrow weight. Then there's also an FOC estimator that way you can spec out how you want your arrow. It's really handy I use it a ton.


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## Hoytalpha35 (Apr 5, 2011)

Also higher FOC is going to drop less not more


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## jmann28 (Nov 22, 2010)

Hoytalpha35 said:


> Also higher FOC is going to drop less not more


You're saying the higher the foc, the less it's going to drop?? You sure about that?


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## Hoytalpha35 (Apr 5, 2011)

I'll find the website with the info, but 1% higher FOC equates to 2% reduction in drag. Higher foc arrows are less affected by wind so there must be some truth there. This info was also given to me from a knowledgable archer.


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## grantmac (May 31, 2007)

Higher FOC only translates into better trajectory if you keep the initial speed the same. That is basically impossible unless you reduce the shaft weight.

-Grant


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## rsb_924 (Mar 11, 2006)

amp713 said:


> Rsb-I knew some of those facts and that was the reason i wanted to try them but there was a lil info in there that was new or revised so thanks for sharing all of that. How did your 28% foc's shoot? and how were you getting them that high? just weighted inserts? or were you doing a larger broadhead too?


they were flat shooting out to about 30 yards. no they did not have any weight inserts. but did have heavy BH. they were wood shafts. ???? my shaft looked like a revers pool cue with the heavy end up front. may look funny but it worked with out having to have foots on the shaft. this is a picture of the shaft and the outcome of a 32 yard shot








hoytalph.. is right an u for got one other thing better penetration.


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## amp713 (Jul 4, 2010)

Your heavy FOC is going to have a different trajectory than an arrow set up with less more than likely but its going to be able to go way further downrage with less things affecting it, like cross winds. 

AND yes penetration is going to be a huge part of the pro's too!


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## amp713 (Jul 4, 2010)

K checked mine today, Im at 465 grains total weight and 11 percent FOC, Thinking about maybe going to lighted knocks though, so ill probably add a small weight on the front to bring me around 12-13 but they are shooting good now!


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## rsb_924 (Mar 11, 2006)

keep in mind that a lighted nocks are about 20 to 24 grains each not like a regular nock at 9 to 13 grains.


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## amp713 (Jul 4, 2010)

Ya i knew they were a lil heavier so thats why i was hoping to add weight to the front, maybe a 30-50 grain change somehow so counter acting and adding more FOC


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## Bulldogjohn (Jun 9, 2012)

FOC For The Overly Concerned Just kidding guys here is a great video that explains alot. https://www.youtube.com/watch?v=ot09tI3L_xY


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## rober2wt (Feb 12, 2017)

amp713 said:


> Ya i knew they were a lil heavier so thats why i was hoping to add weight to the front, maybe a 30-50 grain change somehow so counter acting and adding more FOC


i think you are over thinking it... if you were making large jumps in percentage and carrying that out to the extreme then i would say, "ok, sounds like a fun science experiement." i spend all day at work zoomed in on CAD models working in fractions of a mm, only to look at what took me hours to do with a scaled reference and realize how minuscule it really is. but FOC? i wouldnt spend all day splitting hairs.

for example the addition of the lighted nock on a 450 grain arrow will change FOC by a percent or less. and then you are going to stretch that out over football field? how do you intend to quantify the difference? i agree, physics say that yes, it will make a difference and change the flight characteristics. but is that change even perceivable? is splitting fractions of a percent going to make *THEE* difference? even out of a hooter shooter, id be willing to wager that the difference in a percent or two is marginal at the very best.

you could be the best undiscovered shooter in the world. who knows. but i do know that i am not the best shooter. with that said, i stretch out to 100 or more every chance i get. the equipment usually performs very well, the larger variable is me. (for constructive purposes im shooting a 400 grain 330 spine da torch with around 12% FOC. i played with different vains and saw little difference that wasnt caused by my own error. as long as i stay in the shot the whole way, it usually hits where i was pointing)


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