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If you want more FOC, increase your spine a little to start with and go from there.

I am currently doing a .330 spine and 17% FOC with a 150 grs up front.

For that setup, I'd be in the 450-525 range for over all arrow weight. I'd do it with a shaft that allowed me to shoot a good 125 grain head. And, like in the past, I'd kill everything from deer, bear, and elk that I hit in a vital area.

God Bless

I have a PSE Vendetta set at 69-70#, 26" draw, I use Gold tip trad arrows, 50 grain inserts, Magnus 2 blade stingers or buzz cuts @ 150. I touch up the broad heads with a 1000 stone and then strop with leather and a white compound. My arrow weights are 535-540, i weight each arrow to see what they are. I believe my FOC is around 23%.

The point, this year I shot a small 6x bull 35 yds broadside. The arrow/ blade nicked a rib and punched through the far side shoulder blade high for a pass through.

The downside is the arrows loop, however when they hit they hit and punch through!!!

Broadheads are a solid tip "COC" Wac'em, VPA, G5 type head.

Use this link to calculate your foc.

My small diameter arrows weigh 453 and this years wt deer arrows are 500.

Bow shoots quieter with heavier arrows. Less energy loss that becomes noise.

I don't care to waste my time and show anything quantitatively. I do know that this year, a quartering to shot broke the shoulder at the scapula/humerus joint and penetrated out the opposite side just behind the shoulder. Broadhead was a solid 100 gr VPA 3 blade.

Some will say shoot a heavy arrow, which is fine. And some will say FOC is "Kool Aid" pixie dust magic and it doesn't matter, which is fine too, I suppose.

My setup works well for me. I don't know much, but I know that. Nothing really to overthink, just a little common sense mechanics/dynamics that's all.

I calculate foc whenever a change is made or considered when building arrows.

Wraps, big plastic vanes, lighted nocks, and 100 g points are ingredients for trouble.

Absolutely you should shoot a heavier arrow if you want better penetration on elk.

Like said make it over 400gr. I personally went all the way up to 500gr and get much better penetration than the first elk I shot with a 380gr arrow.

Easy way is to go to a stiffer spine arrow which will up your weight by about 20grs, then shoot a 125gr tip.

If you are serious about penetration and FOC go with the brass inserts if they have them for your arrow (I would should a 340 Axis arrow with 50 gr. brass insert then you can keep your 100gr tips and slick tricks and forget about the Rage:)

Personally, I'd bet you are out of tune, which is causing penetration problems. My son gets complete pass-thu's with his Slick Trick's at 26" and only 45# with a 390 grain arrow.

Side note: I would recommend against Rage heads on an arrow with that limited energy.

So for anyone else on here who is overthinking the process with "FOC this, broadhead weight that, whatever", come back and give s a report after you've killed 50 elk.

To x-man's post, with my stickbows I get great flight and results shooting full-length 400s, when my draw length is 29" and the proper spine for that with a 53# recurve should be 500. That extra length and spine variability allows me to do lots of things with head weight, etc.. that I couldn't do with the 500s at my "correct" draw length.

Look into replacing vanes with feathers and using QAD nocks or similar. A significant increase in FOC can be had by doing so.

Having said that, arrow placement, animal movement, broadhead design and the bow's tune will have far more affect on penetration.

A guy in Florida traveling to hunt in Montana as opposed to a guy already living there would in effect have less days to hunt and more expense, assuming the NR differential of a tag was irrelevant and the same 4 days of PTO were used during the week. Didn't mean for a guy that could hunt for 25 days straight...

Same can be said about a guy who has killed 103 whitetails 25 miles from home as opposed to the guy who has only killed 5 856 miles from home.

The short of it all is that there are several setups that will effectivily kill, we all have our favorite. But the one thing common to all of them is good arrow flight from a properly tuned bow.

That's true but It really has nothing to do with Killing 50+ Elk with a setup that by believers that FOC matters shouldn't be effective.

A guy with a higher FOC, over time (and money invested), can draw the same conclusion that his setup works just as good after he's shot 50+ elk as well.

It doesn't matter how many elk someone shoots with their setup, as long as it kills the way it should. 50+ elk means as much as the guy who can and will only be able to shoot 10.

Repeatability is repeatability, and one setup repeated multiple times doesn't mean it's better...

I've yet to see anyone, including me, show anything that quantifies it as a benefit or not. Arrows aren't the same, the target "media" is bogus, you name it.

All anyone can do is state why or why not they prefer it.

It is by the grace of god that many successful bowhunters are out in the field right now. Otherwise they may have learned the set-up they have been killing animals with for years is theoretically ineffective and quit bowhunting.

He did manage to eventually kill a moose, but I'd venture that he went overboard vs. what is truly necessary, especially after seeing the results of the little 60+ year old lady I helped last year on her moose hunt shooting a 45# longbow, 450 grain wood arrows, and FOC probably around 12%.

You need to spend more time on the internet - you can't kill a moose with that...

People act like its this new phenomenon that only exists if you measure it. I was calculating and setting up high FOC 20yrs ago, but not for hunting, I could've cared less considering my avg shot was probably 17yds and my target was a basketball.

Maybe you can go overboard, but within the confines of typical components available, it's difficult for a compound setup to get much over 15% - 16%. And that by not adding anything extra to the nock end and about 150 grains to the point. On most setups that will get you about 500 grains total weight, which also improves penetration.

I've only killed about 2 dozen elk with a bow and a few other 'larger' critters. But no matter what I'm hunting, I do all I can to get the best results possible when something out of my control doesn't go as planned. I have TOTAL control of my set-up and shot discipline (including shot distance). Not so much, once I loose the arrow.

Does it really take 50+ or would 10 work?

To LINK's point, the OP's question was "what percentage of FOC should I be at?"

The answer was provided by WV in the fourth post: "Shoot a tuned arrow of common sense weight, with a good broadhead and forgetaboutit. You fellas shooting these compounds really over think this. You are shooting something with enough power that arrow weight of common sense isn't going to hurt your long distance trajectory. So, put a decent amount of weight into it, with a good broadhead and, prepare to dig your arrow out of whatever is behind what you want to shoot. After it goes through it."

"For that setup, I'd be in the 450-525 range for over all arrow weight. I'd do it with a shaft that allowed me to shoot a good 125 grain head. And, like in the past, I'd kill everything from deer, bear, and elk that I hit in a vital area."

I've yet to see anyone, including me, show anything that quantifies it as a benefit or not. Arrows aren't the same, the target "media" is bogus, you name it.

All anyone can do is state why or why not they prefer it."

"The answer was provided by WV in the fourth post: "Shoot a tuned arrow of common sense weight, with a good broadhead and forgetaboutit. You fellas shooting these compounds really over think this. You are shooting something with enough power that arrow weight of common sense isn't going to hurt your long distance trajectory. So, put a decent amount of weight into it, with a good broadhead and, prepare to dig your arrow out of whatever is behind what you want to shoot. After it goes through it.""

People spend waayyy too much time fretting over what other people are doing. Exactly, forgetaboutit.

This should show everyone the uselessness of uncontroled "tests", for those on one side of the debate are obviously quite wrong. Which side is it?

I don't give a rat's ass what somebody else uses, or what some nerd thinks he has proven by so-called "controlled tests". There are too many variables in what we do and with the equipment we use. The results that matter to me are big animals lying sideways on the ground.

You like to argue about this stuff on these types of threads. Usually I mostly agree with your points, except when you go rhetorical rather than factual. However, nowhere have you addressed the OP's question. How about trying that?

There are some advantages to XX% FOC, obviously those advantages are greater to a few than most. UFOC may be taking things to an unnecessary extreme only valued to those who do so.

I can't decide whether I enjoy foc threads or rage threads the most.

That said, I may be a little too late, Jaquomo, pretty well nailed it, especially the color commentary.

Yet you some how know that one of those variables, FOC, is not a major factor. How do you do that? You may be right, but the highly touted Ashby comes to the opposite conclusion.

I just find it interesting how people with so much experience can be so cock sure of their opinions (for that is all they are) yet be such opposing points of view. And you both shun any controlled tests. Plenty of time to post on the internet, but no time to come up with facts.

As for the OP's question, it should be obvious from the responces thus far that no one knows the answer for sure. Everything and anything seems to work. Whom is he to believe? A rock on the end of a stick, shot by a bent stick has killed more game than any other setup. Does that help?

Purdue, The reason people with so much experience can be cock sure of their opinions is due to experience. It's hard to argue with experience. When there is such a wide range of reports of lots of animals killed with such a wide ranging percent forward that common sense tells us it's a factor that doesn't matter. It's not worth the effort to worry about it. If you want to that's fine but as far as solving the Op's question, look to other issues, because foc is not likely the culprit.

I believe any conclusion regarding FOC and arrow performance has to be done with a degree of opinion and or faith mixed in.

But the argument goes back to why fret about it? even if Ashby was correct, about foc. there is such a wide range of what works that the conclusion must be that it really doesn't matter.

It's not like you can see benefit by degrees, You hang a heavy broadhead off an arrow, your balance point moves forward, it works. You put a lighter broadhead on the arrow, your balance point moves toward the middle, it works, what have you concluded? They both work, why worry about it?

Because one works better than the other, for reasons that are determined by physics. The only question is by how much. What we agree on, is that it's difficult to quantify. If the shot is perfect, it's irrelevant. But if you only get the equivalent of 1/4" additional penetration through bone, and you only have 1/8" more bone to get through, the arrow may go through enough additional soft tissue to turn a bad shot into success. Since it's just as easy to set up and tune a 15%+ arrow as a 10% arrow, why wouldn't you?

That's still just opinion. You can't isolate the FOC component of the system to test just the effects of that. You cannot prove that there is any benefit. You cannot prove that any added penetration, big or small in any given shot, is a result of one factor or another. It's not provable, there are too many variables. the only thing that's provable are killed animals.

Purdue with questions about uselessness? There goes your subject matter expert status on the topic.

The overall weight of his projectile overshadows this poor FOC, but doesn't hinder his penetration and it sounds like his accuracy to 60 is pretty decent.

I understand the premise of FOC relative to projectile stability, but the penetration significance is (as stated) dang near impossible to prove.

Dynamic spine

Every time an arrow impacts something there are deflection forces, again unless all the stars just happen to align perfectly. Any time the deceleration forces deviate from exactly in line with the longitudinal axis of the shaft, drag increases, negatively affecting penetration. Once the point starts to penetrate, it becomes the balance point or fulcrum, and that changes constantly depending on the tissues penetrated, but the fulcrum remains in the target somewhere, and the farther forward the weight, the less mass behind the fulcrum to continue "pulling" it off line.

Again, you can argue to what degree, but it's there to some degree. Just the increased stability of increased FOC makes it desirable, with the only downside being aesthetics (pretty wraps and light shows).

It takes more effort to create an arrow w/ UFOC than simply screwing on the popular 100-125gr bh. In fact not many here can achieve UFOC twisting on a simple light 100gr bh, you'd need something else adding weight up front. Consequently you'll most likely sacrifice velocity which in the end would require more precise yardage estimates.. which could lead to less accurate shots.. which we all can agree is the most critical variable of all.

LOL, are you saying that the dynamic spine changes with a change in FOC ? I think, or at least hope, that everyone already knows that. Are you suggesting that the dynamic spine must remain constant while changing only FOC in order to have a valid test? LOL

The whole point of changing the FOC is to change the dynamic spine which occurs when you change the arrow's center of gravity (FOC).

See Ziek's explanation.

I don't agree. While it is an important variable, it's one you have complete control of. You can ALWAYS limit your shots to those you are confident in, including within your ranging ability (with or without electronic help). Increased speed mainly allows more confidence at longer distances. I've never shot more than 240 fps and have NEVER felt handicapped at reasonable bowhunting ranges. Many successful bowhunters do with much less speed than that. Speed is the LEAST important factor when setting up a modern compound bow and using a "normal" range of arrow weights. Certainly up to 9 grains/pound of draw weight which is more than most would get to even at 15% - 17% FOC.

The OP never asked about UFOC, which most of us recognize is very difficult to achieve with readily available components and tuning with a compound bow. But if it WERE possible to have 90% of the total arrow weight right at the tip - sign me up! In the meantime, I'm eliminating everything superfluous from the nock end (mainly wraps and batteries) and using more than 100 grain point (at least 150 total) in front.

I also do a similar analysis on every component to get the best compromise in characteristics, with penetration potential high on the list. Again, I have TOTAL control of everything UNTIL my brain releases the arrow. After that, success rides on what the arrow/target actually does and the decisions I already made. Make an honest attempt for the best shot, but plan for the worst hit.

> 19% to be measurable. That's probably why most don't see any benifit to higher FOC, they never reach the threshold.

That's exactly what I'm saying. Don't forget, we still have to launch these arrows somehow. And since you already dismissed the vertical drop test, that means the arrow must be launched from a bow in order for the test to be accurate. Hence my remark... dynamic spine must be constant when launching the arrow from a bow. It's the only way to make sure each arrow regardless of FOC retains the same amount of energy at release. The more the arrow shaft bends, the less energy it retains moving forward.

You still wouldn't have a "valid" test. Most of the advantages of higher FOC occur at impact and are a result of the increased stability during deceleration (increased ability to resist deflection to some extent). You couldn't use a stationary, homogenous target material to measure penetration. You would have to set up a test with the exact same deflection at impact that was repeatable, or close to the same with a very high sample size to make it statistically valid.

But in the real world, why would you bother? If assembling an arrow with higher FOC results in a more stable, stiffer, heavier arrow, all factors that increase penetration potential, and have other desirable qualities as well, it still makes sense to do.

"It's the only way to make sure each arrow regardless of FOC retains the same amount of energy at release."

Your thinking is backwards. We WANT to see how different FOC's through their resulting different dynamic spines affect energy loss, both at the launch and especially at contact. That is why your dropping an arrow from a silo was bogus. There was no loss of energy when you let go and virtually none upon impact. What you want to keep constant is what causes to differences in penetration. If you could keep dynamic spine constant, there will be no difference in there performance. Arrows of different FOC would then be virtually the same arrow.

See you would have to prove that all the people killing piles of elk with arrows that shoot a broadhead with 10%foc, would have ben better off with an arrow with 20% foc. or 50% foc. Impossible to prove.

"But in the real world, why would you bother? If assembling an arrow with higher FOC results in a more stable, stiffer, heavier arrow, all factors that increase penetration potential, and have other desirable qualities as well, it still makes sense to do." You wouldn't bother, you would assemble the arrow based on what you feel is best and what gives you confidence.

In my opinion this is a parameter that at best is practically if not totally immeasurable and is given way more credence than it deserves.

But you can also create these very things without changing your foc.

"Ask yourself why a dart is constructed like it is, heavy FOC makes for a more accurate dart, works like that in arrows as well. Shawn"

try launching the dart like you would an arrow, with your index finger at the back end in the center of the fletch, report to us how it works out.

It has been proven. The problem is the inability of some people to understand it or to accept it.

I've ran controled 5 shot samples of arrows with 5% and 19% FOC and did see a very small increase in penetration through foam (.15").

As mentioned above, according to Ashby, a measurable increase starts at FOC levels above 19%.

"What is FOC?"

It's an acronym or Front Of Center. It's a way of relating the center of gravity location relative to the arrow's length. (If all arrow were the same length, the FOC expressed as a percentage would be unnecessary. Then only an inch measurement of the center of gravity location would be needed.

The heavier the bone that is encountered, the more a high FOC helps.

Understanding it is a problem for a lot of people.

Ashby did a pretty comprehensive study and determined that there was no penetration benefit to increased FOC within the range typically used by bowhunters (10%-15%). Signficant gains were noted above 19% FOC, which is pretty challenging to acheive for most compound shooters using readily available components.

Bob dodged a bullet there. ;-)

Ashby did however determine that there was a threshold that is reached with an arrow weight in excess of 650 grs. that greatly increases the potential for penetrating heavy bone.

It is very interesting how many bowhunters read Ashby's work and modify their equipment to try to take advantage of some of the principals derived from his work, but do so in a way that his work suggests doesn't help meaningfully (e.g. increasing FOC from 10% to 15%). This speaks to the lack of understanding Ziek referenced above.

Just because the results are very difficult to quantify due to the difficulty in replicating the exact same impact, doesn't mean they don't exist.

But many are correct. It's not that complicated. Don't add any crap on the nock end, screw on a quality COC BH of 150+ grains, choose components to tune it, sight it in, forget about the chrono, and go hunt.

I've never seen anybody shooting a 500-600 grain EFOC arrow with a 2" mech up front...

interesting... prolly couldn't get his fixed head to fly right out of one of those newfangled wheelie things with all the EFOC.... heheheheheheh....

If anyone has written proof that shows conclusive evidence one way or the other, please share. And please make sure it is scientific proof, not a back yard test. EVERY detail MUST remain constant EXCEPT FOC in order to prove it. To say otherwise, is refuting science and inserting personal opinion.

Impossible. Changing FOC, by definition, changes dynamic spine at launch AND at impact. So you can't just isolate FOC. And the science says that changing dynamic spine DOES effect the performance of the arrow. That's like saying scientists haven't found any planets outside our solar system. It can't be "proved" until someone actually sees one. It's science and physics that tell us they are there.

I comprehend the theory, and I believe there is some validity to it, but to be able to quantify advantages then apply them to reality is near impossible.

Show us the light.

To what end? IF there were only ONE equation, there would be so many variables it would be more complex than most could understand. I readily admit I couldn't recite the math used to identify the existence of planets, nor could I come up with the math that you suggest. At least not without considerable effort and research. The bottom line is, I DO understand the principles. Besides, the fact is, the advantages of increased FOC in better launch "forgiveness" (faster recovery out of the bow), arrow stability in flight, and x-wind performance is worth pursuing. Take into account ANY increase in terminal performance, at most a possible insignificant reduction in speed, and the benefits should be obvious.

Im sure some of you have seen this Demo before and even though it has no real scientific high tech tools it still shows validity, at least in my mind that there is something to FOC and it compares apples to apples. Same straw same projection method, weight forward and added more weight forward.

FOC demo using soda straws http:www.alaskabowhunting ... - YouTube

I readily admit I can't prove it or maybe I should say disprove it.

What I can prove is a lot of good bowhunters who have been bowhunting for more years than many on this site have been alive, and piles of dead animals to their credit without ever having considered or worried about where their FOC falls, Some right in the 15% range some much less. That"evidence" suggests that if there is any merit to it it's so miniscule as to be a non factor.

And this from a guy that drops arrows from a silo into sand to test FOC affect on penetration.

Ok, in addition to keeping everyting constant except FOC, what else is require to satisfy your valid test requirement? Is a sample of 10,000 required? Do the arrows have to be shot from 10 different bows? Do the arrows need to be shot both toward and perpendicular to magnetic North? Must a silo be involved?

Exactly what is necessay, in your mind, for scientific proof?

Ding ding ding, we have a winner.

It can't be isolated so how could it be given the credit. All we know for sure is that added weight improves penetration. Where you put that weight does not matter as long as the dynamic spine remains the same. Since we cannot isolate only one variable at a time, it will never be more than opinion.

I believe those guidelines are well established and published worldwide. Are you confident you could publish your results in the scientific journal for all the world to review and critique?

Do we? Adding weight changes the velocity. All the vaiables except weight were not kept constant. It's an invalid test and therefore the results are bogus. And the test has not been published in scientific journals and peer reviewed. LOL

No one is arguing the validity of FOC relative to stability. To suggest someone is shooting 0% or less FOC is asinine. Of course increasing their FOC will increase penetration simply due to increased stability, hell they might even hit the target too!

How about this, lets say the avg joe shoots ~12% FOC, prove that increasing this FOC 2x, without increasing overall weight, will significantly increase his penetration.

Describe a test that would satisfy you. Or would you rather critisize the test afer the fact like most people do. Most will only vanidate evidence that substantiates their prior believes, no matter what the subject. So let's get some ground rules.

Let me repeat 1/8"... let that sink in folks. SO increasing FOC 4x gave you next to nothing more than a little over an 1/8". An 1/8" is less than most broadhead's tip!

1/8" is insignificant. A control sample of shots will have that much or more variation. Again, as many has stated, the significance is minimal at best. Is that worth the effort? If you say yes, by all means have at it.

Ballistic gel would be a start, followed by a hooter shooter, and since the quantities are [obviously] very small very accurate measuring tools will be required, and an accurate chronograph (equal velocities). Shot distance is relevant as well, at what distances does the projectile stabilize w/ different FOCs? And a control group.

Ohiohunter, I agree, .15" is a very small increase in penetration. However, the test medium was foam. I would think a high FOC arrow would perform best when it hits something hard. If an arrow's deceleration is slow, the arrow will not flex as much and, as I discovered, one of the main benifits of high FOC is lost. It was after I ran my test thet I heard Ashby's tests were on bone. Maybe balistic gel isn't such a good idea.

No one hunts with a Hooter Shooter, is that realistic or necessary as long as the arrow has stabilized before it hits? "and since the quantities are [obviously] very small very accurate measuring tools will be required."

Like what? Also, what distance, what velocty, what FOCs what sample size, double blind?

"Like what?"

to start with...a microscope, so any benefits can be seen to be measured.

Will an ufoc arrow penetrate more than a lesser foc arrow in the event bone is impacted. I suggest gel and thin medium press board of some kind. Maybe the stuff peg board is made of. Heavy bones are hit at the entrance and exit, a box could be perfect, well ideal I suppose.

Idk how some guys use their phones for this stuff. Killin my eyes.

Jaq, my next hunt isn't until the 22nd muzzleloader Muley and work is slow.

Obviously you didn't study the test results did you. No, the velocity was not constant, but the KE was, and still the heavier and larger drag projectile out penetrated the smaller faster projectile.

ohiohunter, OK, melamine for the outside layer, backed with gel. However, gel is very expensive. Would foam satisfy you?

What distance, what velocty, what FOCs, what sample size, double blind?

Anyone else have input?

As long as it is new foam. 20yds ish seems ample. I'd use a typical setup for the control, just twist on 100gr or 125gr tip and no added weight and measure foc.. 100's are most popular. Then I guess 20% and 30% roughly, at what point is it considered ufoc? Test the 5 shot adequacy by avg the first five then if materials allow try for 10.

No need for double blind, I trust ya, just video it so the "special people" can scrutinize you for not shooting animal flesh, hahaha!

I honestly think the melamine will increase the shaft's influence on results.

What do you think? Are the parameters sound or need modification? Also I'm curious about the methods you will use to adjust FOC while maintaining adequate spine.

Any other suggestions?

It's not rocket science, it is physics. At a high school level at that.

And there's the proof. Because they didn't know or care, FOC has no affect.

But that sentiment is close to to what I have been saying. In the REAL world, if you choose components to make an arrow with higher FOC as a goal instead of choosing components to achieve some increased arrow speed or aesthetics, you will have a much better performing arrow. ALL the resulting changes required when you increase FOC also increase penetration performance. So it's irrelevant how much of the increase is just from increased FOC. The resultant package is better.

I'll go along with that. I don't believe that FOC by itself is the answer but if it causes other changes such as stiffening the spine and adding weight within reason, then it's a benefit.

So now you're into name-calling. How mature.

Listen, science tells us without doubt that a heavier object(bullet in this case) out penetrates a lighter object (same shaped bullet) with same KE, no matter the test medium. Even though the heavier object is slower and larger.

That is why I made the statement "All we know for sure is that added weight improves penetration."

I can't believe you've wasted this much time and energy trying to prove that statement wrong, when it isn't even my conclusion. If I state that the Earth has only one moon, will you spend as much energy refuting that as well?

My concern is how the FOC is changed via weight distribution. If the weight isn't uniformly distributed the results will be skewed.

Here is a question for the number crunchers, optimum KE vs optimum momentum of a given set up... which performs best?

Agreed, but in the study I was pointing out to Purdue, KE was the unit used to compare the bullets. He also seems to think that KE is more suited to archery than ME.

Huh? The definition of a change in FOC IS that the weight distribution is changed. It is also extremely difficult to to maintain the same dynamic spine while changing FOC. There are two dynamic spines that effect performance; one at launch and one at impact, and they are inversely proportional. Increase FOC and you decrease dynamic spine at launch and increase it at impact. That's pretty much the point. To keep the same dynamic spine while changing FOC you would have to design an arrow with variable dynamic spine forward and behind the CG that you could control.

I think those are doable testing parameters. I'll know more when I get into it. The 20% FOC is no problem, the 30% FOC will be vary hard to get. According to a graph I saw from Ashby, there is virtually no change in penetration from 19 to about 25% FOC (and he was increasing arrow weight).

"If the arrows weigh the same shouldn't velocity be relatively the same?"

What I meant was, is there a minimum or maximum acceptable velocity for the test? In other words, will a test at 40 ke be as valid as one at 80 ke?

The test will be ran with field points. Is that a valid test ?

How can the FOC change if the weight is uniformly distributed? Do you even understand what FOC is?

Weight distribution, as I stated before as the test arrows are weighted they should illustrate a hunting arrow. No one in their right mind puts a hunk of lead in the middle of their arrow as a counter weight. It would absolutely distort results vs using weed whacker line or similar weight distribution. If the counter weight is concentrated in the middle it would reduce the actual effect of the remaining shaft.

Field points are fine, I think at impact the conicle point will exaggerate the premis compared to a trocor or coc which would increase penetration thus taking reducing the effect of shaft.

Then you figure out how to change the FOC while keeping the weight constant and then run your own test.

imagine that

And that's why some of us just say what we're doing and don't care one bit about proving why or worrying about what someone else thinks we ought to do...

"No one in their right mind puts a hunk of lead in the middle of their arrow as a counter weight. It would absolutely distort results vs using weed whacker line or similar weight distribution. If the counter weight is concentrated in the middle it would reduce the actual effect of the remaining shaft."

How do you know this? If the mass that you think should be evenly distruted is instead concentrated at one point, both ends of the shaft lose mass which DECREASES their inertia. This should enhance their movement. However, when the shaft tries to bows due to column loading, the increased mass now there INCREASES inertia at that point. This should decrease movement. Pretty much a wash as I see it.

HDE, anything you don't like about the test parameters or will you wait until after the the test to complain?

Most will discard your test if your arrow doesn't represent an actual arrow. As I said, no one puts a 50gr brass insert in the back or middle of their arrows. Why in the world would I suggest a 0% FOC arrow in a FOC conversation? No one is shooting 0% FOC.

Lets try this again.. counter weights to achieve certain FOC should NOT be CONCENTRATED at some point in the shaft, whether you think its a wash or not it is not applicable to any archer.

I cant get the link to work from my work computer but copy and paste below in your search engine.

FOC demo using soda straws http:www.alaskabowhunting ... - YouTube

BF..Thank you mr obvious.

Only at launch. It will be just the opposite at impact. You have suggested how to account for that at launch (increased steerage), but any attempt to manipulate overall weight other than just changing point weight, skews the results at impact.

"counter weights to achieve certain FOC should NOT be CONCENTRATED at some point in the shaft..."

That's exactly how you get significantly more FOC. By concentrating the weight at the front of the shaft.

"Most will discard your test if your arrow doesn't represent an actual arrow."

Exactly. To significantly increase FOC, an "actual arrow" will be heavier and/or stiffer.

"As I said, no one puts a 50gr brass insert in the back or middle of their arrows."

Maybe not 50 grains, but plenty of guys are putting batteries in their nocks. Combined with a 100 grain tip, it's a poor choice.

The soda straw demo only addressed arrow stability, it didn't show penetration, although much can be inferred from that, and better arrow flight alone will also increase penetration.

Only at launch. It will be just the opposite at impact. You have suggested how to account for that at launch (increased steerage), but any attempt to manipulate overall weight other than just changing point weight, skews the results at impact.

You are wrong, changing just the tip increases overall weight thus increasing momentum which does not isolate FOC.

"counter weights to achieve certain FOC should NOT be CONCENTRATED at some point in the shaft..."

That's exactly how you get significantly more FOC. By concentrating the weight at the front of the shaft.

NO SHIT, ITS CALLED THE TIP. AKA FIELD POINT, BH. I'm pretty sure that is a characteristic of a typical arrow.

"Most will discard your test if your arrow doesn't represent an actual arrow."

Exactly. To significantly increase FOC, an "actual arrow" will be heavier and/or stiffer.

Your point? The objective, in order to test the hypothesis, is an attempt to isolate FOC of an arrow that someone would potentially use, not some contorted contraption used only for testing.

"As I said, no one puts a 50gr brass insert in the back or middle of their arrows."

Maybe not 50 grains, but plenty of guys are putting batteries in their nocks. Combined with a 100 grain tip, it's a poor choice.

WHATS YOUR POINT?

The soda straw demo only addressed arrow stability, it didn't show penetration, although much can be inferred from that, and better arrow flight alone will also increase penetration.

Name one person who shoots an arrow with all of the weight either in the middle of the shaft or at the back, please do. When you find this person (based on your BS above its probably you) please post a video of them shooting such arrow out of some high energy cammed bow, i think it would be comical.

Oh zeek, next time could you please take more out of context. It really pleases me to know someone who does not speak the language is at least trying to fit in.

ohiohunter. My point is IF you try to isolate FOC by adding weight ANYWHERE on the shaft, even if evenly distributed, you skew the results in another way.

No one is thinking critically about what happens at impact. In flight, the arrow rotates around the CG, (with arrows, that's referred to by FOC). The more FOC the more stable the arrow because there is a greater lever arm aft of the CG than forward. That STOPS at impact. The tip imbeds in tissue and becomes the fulcrum. Basically, the lever arm is the full length of the arrow. ANY weight behind the tip, no matter where it is or how it's distributed, will work against penetration potential if there is ANY misalignment between the arrow's longitudinal axis and it's direction of travel, or if there are ANY other deflective forces. AND there is small chance that there won't be. (Column loading will also be affected by changing overall weight because all the deceleration force occurs at the tip). The more weight that is behind the tip, and the farther the weight is from the tip, the worse the results. So weight alone is not as important as where the weight is concentrated. Of course, things continue to change rapidly as the wound channel influences the fulcrum point. But the farther forward the weight is concentrated, the less deviation will occur and the more chance of some recovery of the arrows initial path before impact, which is what is desired for best penetration.

By the way, who is "zeek"?