FOC issue.

[Smossy]

I finally just did the math/measurements on the correctly cut length of arrow that I intend on hunting with, With Field Points my FOC is around 9.1666% and with Broadheads my FOC is around 8.870%

Not sure what all that means but I imagine its supposed to be alittle higher, Im looking for around 12% and not sure where to go from here, to add weight to the front? To the back? What kind of things do you guys usually add to play with the balance, etc...

Goldtip XT Hunter's 8.2gpi - Length @ 28.750" from nock throat to tip insert. 7/8inch+ for FP and for those math guru's BH is 1 inch.
- Balance came into around 17.750 inches from nock throat to balance point with the FP - and 18.250 with the BH.
Im using 100 grain tips. 2inch blazer vanes set 5/8"inch In from the very end of the arrow, not the nocking point.

Hope thats enough information to have someone help me out. Im not liking the low FOC, it seems very unforgiving and probably lacks penetration. 

[demontang]

How much weight are you pulling? What spine are your arrows? Id guess your shooting 400spine and pulling 55-60lbs?  Ive been playing with foc and flight of my broadheads lately, 9% doesnt seem to be right, they seem to fly better with 12%. I see on gold tips sight you should be in the 10% range, you can do a few things to change your foc but it affects the spine of your arrow. You can add weight to the front of your arrow and get the foc up but loose spine doing this,.My beman ics hunter pro are about 10% and my axis are 12% and the axis fly a little better..  Radsav should chime in I know he is deeper into this then me and can get you a better answer.

[bowhunterforever]

Since this topic came up, How do check what you foc is? Curious what mine is.Thanks

[hughjorgan]

Since this topic came up, How do check what you foc is? Curious what mine is.Thanks

http://archeryreport.com/2010/09/arrow-foc-basics-calculate/

[hughjorgan]

I finally just did the math/measurements on the correctly cut length of arrow that I intend on hunting with, With Field Points my FOC is around 9.1666% and with Broadheads my FOC is around 8.870%

Not sure what all that means but I imagine its supposed to be alittle higher, Im looking for around 12% and not sure where to go from here, to add weight to the front? To the back? What kind of things do you guys usually add to play with the balance, etc...

Goldtip XT Hunter's 8.2gpi - Length @ 28.750" from nock throat to tip insert. 7/8inch+ for FP and for those math guru's BH is 1 inch.
- Balance came into around 17.750 inches from nock throat to balance point with the FP - and 18.250 with the BH.
Im using 100 grain tips. 2inch blazer vanes set 5/8"inch In from the very end of the arrow, not the nocking point.

Hope thats enough information to have someone help me out. Im not liking the low FOC, it seems very unforgiving and probably lacks penetration.

How do you end up with a different FOC, if your field point is 100 grains and BH is 100 grains the FOC should be the same....

Are you shooting 3 fletch or 4? Vanes or feathers? You can lighten up the back end to give yourself greater FOC depending what you do.

You can build arrows with brass inserts to add weight up front, but you will have to probably buy new arrows...

As has been stated you can bump your field tips/ BH to 125 grains from 100, this could pose a problem if you are borderline on spine for your setup. You should be able to look up on gold tips website if a heavier head will work.

[dawn2dusk]

Gold tip offers insert weights you can add. 10 and 20 grains and fairly cheap too. Just another option for you. Pretty easy way to adjust FOC

[Smossy]

How much weight are you pulling? What spine are your arrows? Id guess your shooting 400spine and pulling 55-60lbs?  Ive been playing with foc and flight of my broadheads lately, 9% doesnt seem to be right, they seem to fly better with 12%. I see on gold tips sight you should be in the 10% range, you can do a few things to change your foc but it affects the spine of your arrow. You can add weight to the front of your arrow and get the foc up but loose spine doing this,.My beman ics hunter pro are about 10% and my axis are 12% and the axis fly a little better..  Radsav should chime in I know he is deeper into this then me and can get you a better answer.

62lbs and a 400 spine, yes sir. I texted Radsav about the issue but hes slow on phones so you guys will have to do for now So a 125 grain BH should help?

[Smossy]

Since this topic came up, How do check what you foc is? Curious what mine is.Thanks

http://archeryreport.com/2010/09/arrow-foc-basics-calculate/

Exact website and math I used also.

[Smossy]

I finally just did the math/measurements on the correctly cut length of arrow that I intend on hunting with, With Field Points my FOC is around 9.1666% and with Broadheads my FOC is around 8.870%

Not sure what all that means but I imagine its supposed to be alittle higher, Im looking for around 12% and not sure where to go from here, to add weight to the front? To the back? What kind of things do you guys usually add to play with the balance, etc...

Goldtip XT Hunter's 8.2gpi - Length @ 28.750" from nock throat to tip insert. 7/8inch+ for FP and for those math guru's BH is 1 inch.
- Balance came into around 17.750 inches from nock throat to balance point with the FP - and 18.250 with the BH.
Im using 100 grain tips. 2inch blazer vanes set 5/8"inch In from the very end of the arrow, not the nocking point.

Hope thats enough information to have someone help me out. Im not liking the low FOC, it seems very unforgiving and probably lacks penetration.

How do you end up with a different FOC, if your field point is 100 grains and BH is 100 grains the FOC should be the same....

Are you shooting 3 fletch or 4? Vanes or feathers? You can lighten up the back end to give yourself greater FOC depending what you do.

You can build arrows with brass inserts to add weight up front, but you will have to probably buy new arrows...

As has been stated you can bump your field tips/ BH to 125 grains from 100, this could pose a problem if you are borderline on spine for your setup. You should be able to look up on gold tips website if a heavier head will work.

The broadheads are longer than the field points   Maybe I screwed up somewhere, Im not great with numbers.
3 Fletch 2" Blazer vanes. and Ive mastered removing inserts.

https://www.youtube.com/watch?v=dIto4WoZhjQ

[hughjorgan]

Well do your broad heads shoot true with the current FOC? I would think that 125 grain tip should put you over 10% FOC.

If you want to lighten up the back of the arrow get a hold of some rayzr feathers, they only weigh 2 grains vs the blazer being ~6 grains if I remember correctly.

[Smossy]

Well do your broad heads shoot true with the current FOC? I would think that 125 grain tip should put you over 10% FOC.

If you want to lighten up the back of the arrow get a hold of some rayzr feathers, they only weigh 2 grains vs the blazer being ~6 grains if I remember correctly.

Would it help If I changed everything and went with a 340 spine? Elk247 helped me out with a 6 pack of 340 spiners at 9.2gpi I think it was.

[hughjorgan]

Well do your broad heads shoot true with the current FOC? I would think that 125 grain tip should put you over 10% FOC.

If you want to lighten up the back of the arrow get a hold of some rayzr feathers, they only weigh 2 grains vs the blazer being ~6 grains if I remember correctly.

Would it help If I changed everything and went with a 340 spine? Elk247 helped me out with a 6 pack of 340 spiners at 9.2gpi I think it was.

Don't know, I try a heavy fp/bh to get your desired FOC first.

Did you figure out your FOC on the .340s?

[Smossy]

Well do your broad heads shoot true with the current FOC? I would think that 125 grain tip should put you over 10% FOC.

If you want to lighten up the back of the arrow get a hold of some rayzr feathers, they only weigh 2 grains vs the blazer being ~6 grains if I remember correctly.

Would it help If I changed everything and went with a 340 spine? Elk247 helped me out with a 6 pack of 340 spiners at 9.2gpi I think it was.

Don't know, I try a heavy fp/bh to get your desired FOC first.

Did you figure out your FOC on the .340s?

Not yet, I think the foc came to about 9.8%

Maybe my math is wrong.

[Crunchy]

I've never checked my arrow FOC and the dead elk didn't either. Dont beat yourself up over minor details. Correct spine is more important.

[jgrimes]

You can cut your arrow down so that your FP/BH is just in front of your launcher arm/biscuit. This effectively stiffens your arrow, but it also improves your FOC. I shoot 63 lbs with a 350 spine arrow and a lot of weight up front (~15%). If the BH you like is offered in a 125 gr option that would be a good way to achieve your goal. Cutting your arrows down and adding more weight up front could possibly get you close to the same arrow weight you have now, so that you won't need to adjust your sight much. I enjoy this site http://www.backcountrybowhunting.com/articles/calc/ give it a look.

[RadSav]

340's will only make the problem worse.  Besides being worse on FOC it is not recommended for your current setup.  Even the 5575's are slightly on the stiff side.

But I have a good idea!  Let's use the correct math 

AMO is now the preferred method and the one I use.

Archers Advantage says 11.3%
My math says 11.73913%

Funny that the crazy article with the guy that thinks fletching actually will "steer" the arrow has the same math as I use.  If you use their calculator it too says 11.73913%

17.75/28.75 is 0.6173913 - .5 = 0.1173913 or 11.7%
or 3.375/28.75 = 0.1173913 or 11.7%

Perhaps trying to do math while dehydrated and recovering from a hangover is not advisable.

[Smossy]

340's will only make the problem worse.

But I have a good idea!  Let's use the correct math 

AMO is now the preferred method and the one I use.

Archers Advantage says 11.3%
My math says 11.73913%

Funny that the crazy article with the guy that thinks fletching actually will "steer" the arrow has the same math as I use.  If you use their calculator it too says 11.73913%

17.75/28.75 is 0.6173913 - .5 = 0.1173913 or 11.7%
or 3.375/28.75 = 0.1173913 or 11.7%

Ok so I screwed up somewhere then I take it. Going to have to look into it more untill I achieve the same foc you listed. I want to be able to get this down.

Basically Im sitting at 11.7%?

[RadSav]

Weight distribution of field point profiles and broadheads is too inconsistent to use method 2 with any accuracy.  You can hedge your bets and divide the differences, but as a guideline AMO is the best for consistency.   If using method 2 with broadheads shoot for 10% and if AMO shoot for 12%.

One of my pet peeves is when smart people say that fletching will steer the arrow.  I'm sorry but fletching possesses no intelligence. So if by some act of miraculous intervention it did start to steer an arrow where might one expect it to steer it to?  I won't be placing any bets that it is anywhere near the place I want it to go.  So I would rather just chose the arrows path before hitting the trigger and then let energy, friction and gravity do the rest without relying on divine intervention.

While fletching does assist sectional alignment of the shaft to the targeted flight path and that job is made easier when FOC gives additional leverage to the arrows mass it is the energy stored within the mass that really makes the difference.  More mass in the front the more stored energy in the front.  Now that arrow has more positive energy in the front half and the fletching is applying more negative energy (drag) in the back. 

It's like taking a limp piece of string.  It has no memory, no spine and no directed path of energy transfer.  You throw it forward and it remains for the most part in the same shape it was in your hand.  Only manipulated in form by friction.  Now add energy/mass to one end by tying a fishing weight to it.  Once thrown that weight will hold positive energy.  Now tie a small lightweight parachute to the other end of the string.  When thrown this will create more drag than it's mass holds positive energy thus creating a negative force of energy.  When thrown the two opposing forces will take the once limp spineless string and pull it tight and straight within the targeted path of the throw.

Now imagine if the parachute held the same mass as the weight in the front.  The parachute shape would then loose energy faster than the weight in the front, but the tension upon the string between the two areas of equal mass (weight) would be lost.  It would still fly better than throwing the string with no added mass at all, but the result would not be nearly as pronounced as it was with the majority of mass (positive energy) in the front and an opposing force with leverage in the back.

[demontang]

Radsav your the man    I can only hope ill get to where you knowledge level is

[Smossy]

Weight distribution of field point profiles and broadheads is too inconsistent to use method 2 with any accuracy.  You can hedge your bets and divide the differences, but as a guideline AMO is the best for consistency.   If using method 2 with broadheads shoot for 10% and if AMO shoot for 12%.

One of my pet peeves is when smart people say that fletching will steer the arrow.  I'm sorry but fletching possesses no intelligence. So if by some act of miraculous intervention it did start to steer an arrow where might one expect it to steer it to?  I won't be placing any bets that it is anywhere near the place I want it to go.  So I would rather just chose the arrows path before hitting the trigger and then let energy, friction and gravity do the rest without relying on divine intervention.

While fletching does assist sectional alignment of the shaft to the targeted flight path and that job is made easier when FOC gives additional leverage to the arrows mass it is the energy stored within the mass that really makes the difference.  More mass in the front the more stored energy in the front.  Now that arrow has more positive energy in the front half and the fletching is applying more negative energy (drag) in the back. 

It's like taking a limp piece of string.  It has no memory, no spine and no directed path of energy transfer.  You throw it forward and it remains for the most part in the same shape it was in your hand.  Only manipulated in form by friction.  Now add energy/mass to one end by tying a fishing weight to it.  Once thrown that weight will hold positive energy.  Now tie a small lightweight parachute to the other end of the string.  When thrown this will create more drag than it's mass holds positive energy thus creating a negative force of energy.  When thrown the two opposing forces will take the once limp spineless string and pull it tight and straight within the targeted path of the throw.

Now imagine if the parachute held the same mass as the weight in the front.  The parachute shape would then loose energy faster than the weight in the front, but the tension upon the string between the two areas of equal mass (weight) would be lost.  It would still fly better than throwing the string with no added mass at all, but the result would not be nearly as pronounced as it was with the majority of mass (positive energy) in the front and an opposing force with leverage in the back.

Sometimes I think you just like to type type type Rad lol. Your signature fits you perfectly.
lmao.

Smossy - So Im at 11.7% Foc
Radsav - Yes.


Im not even sure what weight my bow is set at anymore, or what my actual draw length is... Ive had so many numbers, and so many changes going through my head Im going to have to find out all over again.

[BULLBLASTER]

Rad is full of wisdom with all things archery.
Smossy all of those numbers and measurements really don't matter all that much in the real world. It is most important that the bow fits you and is a weight that you can easily shoot. The arrow weight is somewhat important due to laws... draw weight I guess too. Most arrows with a insert and a 100 grain or so tip will have adequite foc. The only time I had it affect me by being off was when I was trying to set up for maximum speedwith a fat target shaft for 3d. A 50 grain glue in tip does not weigh much more than a pin nock bushing and vanes.
Life is much easier if you just focus.on shooting and don't worry about the rest unless something doesn't work.   
Good luck!

[RadSav]

Sometimes I think you just like to type type type Rad lol. Your signature fits you perfectly.
lmao.

Smossy - So Im at 11.7% Foc
Radsav - Yes.

    I opened the link posted to try and figure out your math.  Then I made the mistake of reading the entire link and the mention of "steer the arrow" caught me wrong as usual.  The author is definitely well written and smart, but it just drives me a little crazy sometimes.

I agree with Bullblaster!  Sometimes life is much easier if you just shoot and have fun.  Seamheads like me are rarely ever as happy with their gear as those who see it as a stick and a string that shoots another stick.  There is a reason my family and friends call me a fun sucker

[Smossy]

Sometimes I think you just like to type type type Rad lol. Your signature fits you perfectly.
lmao.

Smossy - So Im at 11.7% Foc
Radsav - Yes.

    I opened the link posted to try and figure out your math.  Then I made the mistake of reading the entire link and the mention of "steer the arrow" caught me wrong as usual.  The author is definitely well written and smart, but it just drives me a little crazy sometimes.

I agree with Bullblaster!  Sometimes life is much easier if you just shoot and have fun.  Seamheads like me are rarely ever as happy with their gear as those who see it as a stick and a string that shoots another stick.  There is a reason my family and friends call me a fun sucker

your no funsucker. Ug ug choot stick with stick and string