F.O.C. / broadhead weight (moved)

[trcytylr]

Had this on the shooter forum:

Can you guys explain to me the importance of heavy weight up front on an arrow.

I read alot of post about adding inserts and heavy broadheads. But seems to me that it would slow down the arrow and cause a good bit of drop in the arrow.

Thanks, I'm still learning!

[Earl Jeff]

To make it as simple as possible, tests have shown that a arrow will penetrates farther if it is pulled through its target rather than being pushed through. I beleive it has a lot to do with arrow (oscellation ?)when it contacts the target.

[Bill Carlsen]

Earl has got it. i have proven it to myself numerous times over the past six years or so. Fpr me, the arrow weight would be the same, 10 grains per pound of bow weight, more or less. A 600 grain arrow with 200 grains up front has significantly out penetrated similar 600 grain weight arrows I used to shoot from much heavier bows with only 125 grains up front.

[Earl Jeff]

Tracy if you want to make some EFOC arrows take a look a Victory Archery arrow HV-3 series they they are 300 to 400 spine and are all in the 6.4 to 6.7 gpi weight.

[JimB]

First order of business is to learn how to properly tune your arrows.This will affect performance more than anything.

After that,high FOC can increase performance and there is no nose diving.Again,learn how to tune before you get serious about this stuff.Since adding weight to the front end weakens the dynamic spine of the arrow( makes it act weak)you have to go up one or 2 spine groups to achieve the high FOC and still be in tune.

It helped me,when switching to carbons,to tune up a regular set with more normal weight heads,then I had a base of reference to increase spine and point weight on the next set of arrows.

If you are just starting out,learning the art of tuning is very important and I personally would get that figured out without the complications of more advanced stuff.After you have a complete understanding of tuning,you could move on from there.See the tuning information at  www.bowmaker.net

He also hits briefly on FOC.

[Earl Jeff]

Jim B makes makes a point. I just figured that anyone messing with High FOC was already skilled with tuning a arrow to there bow?

[trcytylr]

Thanks guys. No I haven't figured out the tuning stuff yet. I thought that was part of the whole process of tuning. I just seen alot of stuff about inserts and broadheads.
 Just got a (new to me) bow from a fellow trad member. I had been practicing with a borrowed ben pearson.
This one is a Jordan Stalker 3pc takedown 52#@28"

I will ck out bowmaker.net

[JimB]

Well,adding or taking away point weight does enter to the tuning aspect.It weakens or stiffens the dynamic spine as do changes in shaft length.

Normal FOC was always considered to be something like 11-15 %.These days some people experiment with and test the benefits of much higher percentages of FOC and I'm told by some smarter than me,that performance increases don't start to show till 19% and above.

A lot of spine recommendations are considering normal FOC and standard weight heads like 125 gr.When you talk about heavy weight up front,most would probably think of 250 grs and on up.Almost any weight can be made to work if you get the right combination of front end weight and shaft stiffness.

I haven't personally used it but a lot of people use Stu's Calculator which is a program you can download and it will give you suggestions on shaft spine,length and point weight.Most say it is very accurate if the correct numbers a punched in.You would still want to shoot and check tuning to verify.You could post a question about Stu's Calculator and I'm sure someone could help you.

Good luck,you are in for a lot of fun.

[Don Stokes]

trcytylr, there's a lot of hype relative to extreme weight-forward arrows, and a lot of flawed logic to support certain claims. This trend mostly resulted from the use of carbon arrows. They tend to be so light that you need a very heavy point to get decent arrow weight, and they tend to be so stiff that they need to be shot full-length with a heavy point to get them to tune properly from moderate draw weight bows.

The fact is, if your arrow is front-heavy to any degree, and if it's tuned properly to your bow, it will shoot and penetrate just fine. We've been doing it this way since way before carbon was used for shafts, and there are millions of dead animals to testify to "standard" traditional archery setups.

Perfect arrow flight trumps every other consideration. Get there first, and then play with things like EFOC if you like to tinker. Extreme arrows are useful for extreme situations, but for the vast majority of us such measures are not necessary for our hunting in the USA. Now, if you're going to Africa or Australia...

[Earl Jeff]

There is also lot of proof through hard work and testing that proves it's effectiveness and yes carbon arrows make it easier to do.

[Ragnarok Forge]

If your truly interested in FOC and EFOC read the Ashby threads in full and ask any questions you have on here.  I went thru them and found a way to obtain EFOC in a 584 grain arrow.  Was it vital to my shooting.  Not really.  Do I feel a lot more confident in my ability to penetrate an elk.  Yes I do and confidence is a big part of good shooting for me.  I personally would not hunt with an arrow that is not optimized.  Perfect arrow flight using an FOC optimized arrow makes it so a 45 lb bow shot arrow hits like it was a standard arrow shot from a 65 lb bow.

Just my way of doing things.  Millions of animals have been killed without EFOC arrows being used.

[Terry Green]

Originally posted by Ragnarok Forge:
 Perfect arrow flight using an FOC optimized arrow makes it so a 45 lb bow shot arrow hits like it was a standard arrow shot from a 65 lb bow.

 

Clay....where did you get that documented fact?

Not trying to be a smart alec....but just want to know where that claim came from and if it is fact.  There are a lot of claims being made lately that are unfounded and being parroted all over the place....and this leads folks to use the wrong equipment only 'thinking' that they are good to go when the are not..  Its a big claim to say the same 45# bow will 'hit like' the same designed 65# bow drawn to the same length.

Where did you get the fact that a simple change in weight distribution on an arrow would make up for a 20# draw weigh reduction?

[Don Stokes]

[Ragnarok Forge]

Terry,

Read thru the latest Ashby Report on the 40 lb bow and it's results.  I used his information from that report for that statement.  I would love to have the time and money to prove it myself with scientific research.  

Thanks for keeping me honest by the way.  I have always appreciated that about this site and your moderation of it. It isn't just recently that folks make a lot of claims without support.  Just look at the KE = penetration that is being pushed by the compound industry as the end all and be all for one great example of this trend.

[Terry Green]

Clay....1st, thanks for the civil response...

There is no way a 45# bow shooting 10 grains per pound (450 grains) with an FOC of 25 or 30% is going to shoot with the same authority as a 65# bow shooting 10 grains per pound (650 grains) with an FOC of 15% (both at the same draw length).  Aint gonna happen...and I don't believe can be proven no matter the money spent.

Again, not being a smart alec,....just don't want folks to believe in some magical FOC and a light weight bow that they can conquer the world more efficiently than with a 20 pound heavier bow with normal FOC.

FOC is a SMALL increment in the grand scheme of thing.  MANY things are MUCH more important to killing animals than what percentage of the weight  forward as long as its 12% or above with broadheads. (the last statement concerning 12% is my opinion on shooting Bheads under adverse conditions afield.  I feel 12% FOC is MINIMUM and 15-18% is much more stable with the hunting shots based on different shooting angles, body contortions, terrain features, weather, etc.)

[Str8Arrow]

Originally posted by Terry Green:
Clay....1st, thanks for the civil response...

There is no way a 45# bow shooting 10 grains per pound (450 grains) with an FOC of 25 or 30% is going to shoot with the same authority as a 65# bow shooting 10 grains per pound (650 grains) with an FOC of 15% (both at the same draw length).  Aint gonna happen...and I don't believe can be proven no matter the money spent.

Again, not being a smart alec,....just don't want folks to believe in some magical FOC and a light weight bow that they can conquer the world more efficiently than with a 20 pound heavier bow with normal FOC.

FOC is a SMALL increment in the grand scheme of thing.  MANY things are MUCH more important to killing animals than what percentage of the weight  forward as long as its 12% or above with broadheads. (the last statement concerning 12% is my opinion on shooting Bheads under adverse conditions afield.  I feel 12% FOC is MINIMUM and 15-18% is much more stable with the hunting shots based on different shooting angles, body contortions, terrain features, weather, etc.)

You just asked the poster before you for proof.  Where's yours? Statements like, "I feel.." just don't cut it when compared to the testing done by Ashby.

[Terry Green]

Str8Arrow,

Answer....simple, momentum created by the 650 grain arrow from the 65 pound bow FAR exceeds the 450 grain arrow from the 45 pound bow that FOC will NOT make up. "I feel" is my opinion based on MY testing and based on 12% as a minimum.  Is only ONE man allowed to test and report?

Where's YOUR proof disputing that?  Where is YOUR testing?

Your quote ..."Statements like, "I feel.." " was ONLY directed to what I feel is minimum for broadheads and hunting....had nothing to do with the facts I stated above.....yes facts until proven wrong.

[Str8Arrow]

If you read Ashby's studies, you'll see that momentum is more easily redirected when it is centered further back on the arrow. Even without doing the studies myself, it makes perfect sense that an arrow that deflects more (lower FOC), will not penetrate as well as an arrow that deflects less (higher FOC).  Add in the penetration measurements taken from shots from the 40 lb vs 65 lb bow and it makes sense.

[Old York]

Where's Doctor Ed?
Maybe he can explain some of this.

How come he doesn't post here anymore?   :confused:    

[Str8Arrow]

I thought I should add that nobody is going to prove anything in regards to this subject. One can accumulate evidence that supports a particular theory and I would say that Ashby has gathered a huge amount of evidence to support his theories.  If you can direct me to anyone else who has recorded a similar amount of evidence with a different conclusion, I'd love to read it. I'm always looking for data that supports hunting a better way.