Wapitibowman
If that happened, something else was causing it. FOC alone does NOT effect trajectory.
The added downwards pull on the front of the arrow should cause a slight increase in drag due to an arrow in flight at less than the ideal angle for maximizing cast.
Wouldn't be a difficult theory to test, if someone wanted to find out.
Pretty sure there's a technical effect, but how much is tough to estimate.
Experienced flight shooters probably know.
If the arrow is flying straight when it hits, it shouldn't matter where the weight is. The momentum will carry it through.
For guys who shoot trad gear, or fingers shooters who may not get optimum arrow flight, those guys would benefit from extreme FOC to a point because more of the total arrow weight is up front with the point. Which is likely why Ashby has better results with extreme FOC arrows. His arrows are fluttering back and forth all the way to the animal. If he had only 10% FOC, he'd not get much penetration at all.
Huh!
An arrow is a ballistic projectile. There is no "added downwards pull on the front of the arrow" in flight. Unlike an airplane with a lifting surface, where added weight in front of the center of pressure results in greater drag to maintain level flight. An arrow DOES NOT maintain level flight.
A properly set up higher FOC arrow could actually drop less than a lower FOC arrow of the same weight because the higher FOC arrow needs less vane area to stabilize it, thus less drag.
I find it difficult to get over about 15% FOC without having a very heavy arrow. I'm at 14.9% with a 550 grain arrow. A reasonable compromise.
Having more of the arrow weight up front has many advantages.
For arrows OF THE SAME overall weight:
You will need a stiffer shaft. While it may be possible with modern bows to shoot an over stiff shaft anyway, there are still advantages of greater FOC.
Greater stability (quicker recovery out of the bow, more forgiving of less than perfect release, better x-wind performance) with the same size fletching, or the same stability with less fletching (less drag=flatter trajectory).
Not only does a stiffer shaft bend less at impact, transferring energy more efficiently for greater penetration. Less weight toward the rear of the shaft also causes less bending at impact.
Arrows often deflect to some degree at impact. Again the more weight toward the nock end, the greater the deflection will be, once started.
While these affects might be slight, they can add up. And to the original question, there are NO downsides to increasing FOC. The more you can build into your arrow, the better.
However, the heavy part tries to drop first. It is prevented from doing so by the air pressure on the fletching and on the shaft, forcing the lighter end to follow behind the heavy end in penetrating the air.
This force being expended comes at the expense of drag being created, in much the same way as the force required to spin an arow fletched with angled fletching comes from the drag created by the fletching in forcing the rotation.
I tested the difference in drop between arrows fletched atraight and identical ones fletched with moderately severe helical, all other things equal, many years ago, and found the drop difference to be about five inches at forty yards, with heavy hunting arrows from my 56# recurve.
I don't argue that there are no other factors involved in the decision on how much FOC is best for each of us. Of course there are and you make the case for them well.
But I still maintain that if you ever test two arrows with all other factors equal and differing FOC, at longer ranges the one with more FOC will impact lower.
It's the law. The law of gravity will try to pull the heavier end downward more than the lighter end, and the laws of aerodynamics will insure that drag will be induced by the efforts of the controlling surfaces in keeping the lighter tail end in line.
As with anything else there comes a point of dimminished returns, moderation is key with most things and arrow weight and FOC are no exception.
I shoot a longbow that has a shelf cut 3/16" from center and can put bullet holes in paper from 8', just like anyone else that shoots a properly spined arrow from a well tuned bow. And yes, thats with fingers.
I honestly find very little difference in trajectory when dealing with FOC from 10%-20%. I think a min/max formula depends on youre own personal set up and needs.
I believe as far as penetration is concerned you probably cant have too much FOC, but there is more to archery and hunting than just penetration.
I have experimented with going higher foc but arrow weight begins to increase and trajectory comes into play, a heavier arrow flat out drops more. There's only so much foc you can get without arrow weight going up. I do however shoot a 60lb bow.
I would try to get the most foc I could get while still maintaining acceptable trajectory and excellent arrow flight. But thats my opinion, your mileage may vary.
I totally agree!
For you guys that don't think an arrow that is heavier on the front will drop faster than an arrow that's lighter on the front at 80 yards I have one question. Are you smokin crack or just trying to sound smart expounding theory's you've never actually tried? Lol! Mike
yep
"How long arrow your arrrows?"
shaft length is 28 1/2"
"That seems odd. And if you shoot 100 grain heads instead of 150 grain heads, are you telling me that you wouldnt see the difference in arrow speed and closer pin gap?"
If I shoot 100 gr heads the arrow is to stiff so I shoot 150's. If I wanted to shoot 100's I would have to increase shaft length. I won't do that because out of a compound I refuse to shoot any arrow that weighs less than 400 grs because I have found that penetration suffers. My 15% foc arrows overall weight was about the same as the 22% arrow so trajectory is the same.
The only way to get more foc is to go to a stiffer shaft then weaken the shaft with more head and insert weight.
"but supposedly they also can be a bit more forgivable regarding accuracy. "
I find this to be true, especially when shooting in the wind.
Out of my recurve I get about 26% foc with an overall arrow weight of 535grs, 10grs per pound. Those shafts have 300grs up front. I can however get 28% if I use 325 up front - total weight 560grs, after that the spine is getting weak. If I cut an inch of shaft I would be good for another 25grs of head weight and would probably hit 29 or 30% foc. At typical traditional bow ranges of 30 yards or less, I see no difference in trajectory.
Therefore how much an arrow drops over a certain distance has more to do with speed than weight. So again, the people that have said foc does not effect trajectory are correct. Total arrow weight being greater and having an initial slower fps is what causes a greater drop over a specific distance.
Then you get into momentum (inertia) which has everything to do with weight (mass). If a 400gr arrow and a 500gr arrow have the same aerodynamic profile and are fired at the same initial speed, the heaviest arrow will resist slowing down and have more speed, less drop and more momentum at impact than a lighter arrow fired at the same speed.
I understand how "logic" may seem to make it appear otherwise, but this is basic level physics. The best video for the effect of gravity can be looked up by researching the hammer and feather on the moon where air resistance is removed from the equation.
Keep it in the range recommended by Easton (they should know a bit about arrows,eh?)8-15% I believe isn't a bad idea. I currently shoot about 17% foc and its a very forgiving arrow that tunes well.
Start putting all of that weight out on the end of the arrow and your form and consistency has to be perfect..any minor flaw and that arrow is less stable/forgiving than with foc in the teens.
Explain this to me. Physics guys say gravity is constant on the same weight. Well, say you have a 600 grain, 4 foot long pole. The wight is spread somewhat evenly. you drop that pole off a high building. It is safe to assume that it will fall flat or there about's.
Do it again with a 4 foot long, 600 grain pole and put 50% of that weight on the tip. which end is going to hit the ground first?
I'm no genius and haven't tried it but, my good ole boy, red neck, dumbtardness tells me it will be the heavier end. Proving in my theory, that trajectory and, how in interacts with gravity is affected by where the weight is.
Therefore, it seems to me that it is very safe to say that since we aren't living in a vacuum, an arrow containing a higher percentage of weight on one end, will see that end being affected differently than a arrow where it is more balanced, when considering trajectory from the same source.
Like I have said, I have never tried the pole thing it and, probably never will. But, I'm pretty sure that I know what the results will be. Just because a flawed physics theory says it ain't so, don't make it not so. Especially when the results we all know we will see in a fair comparison, like one I described above, are in contrast to such a a theory.
I could be wrong like I have already said. but, until someone shows me that I am in real life video, I choose to dismiss the theory stating what doesn't seem possible. Remember, according to Physic theory's bumble bees can't fly ether. God Bless men.
The way I understand it in theory... Mass tends to keep on the same direction, retains energy better. A 400 grain and 500 grain shot at the same speed, all else equal, the 500 grain will retain it's speed better, downrange the heavier arrow will be going faster than the lighter one, even though they left the bow at the same speed.
Weight loaded up front will retain more energy than the lighter weight in the rear, therefore "pulling" the arrow along. In theory.
IMO I'm not sure it has much effect at all in practice as the fletching has so much more stabilizing effect, certainly not much influence with a clean flying (modern compound) arrow to make a difference. When I see guys with <10% shooting 3 and 4" groups at 40 yards and greater.... it would be hard to argue they are doing something wrong and you would gain any accuracy with EFOC. You can however completely screw things up flight/accuracy wise with it.
Might see it in penetration IF the arrow is not flying very well to begin with. IMO it's more of a trad thing. All else being equal, arrow weight is arrow weight. Arguing that a person got better penetration with EFOC, in nearly every case I see that they have increased the overall weight of the arrow to do so. Of course you are going to see an increase in penetration. But likely not by EFOC alone.
what?
you make a definitive statement "The maxima Reds with 100 Grain brass inserts and a 175 grain head produce more foc than anything else"
OK thanks for sharing, but...............
you admit you don't know how to measure
you admit you are guessing
..........and that is supposed to carry come credibility?
We know TBM is your dad, cade, but you have to do better than that dude.
Not really. If you had 15% BOC (back of center) as the arrow hits the target, especially a rib bone, will tend to put the arrow into deflection like a column or beam with a load applied to the top and the bottom resting on the ground. This would cause the arrow to not continue on in a "straight" path to penetrate.
Extra weight at the front is the only thing that really drives the arrow in deeper, that's it and that's all.
Case in point; why can an arrow that weighs 50 gr less and going faster than another arrow (same broadhead, same shot distance) penetrate just as good, if not better, when it's FOC is 16% as opposed to 13%?
At 20 yards I didn't see any penetration differences. but where I was really impressed is on accuracy of the FOC arrow. That arrow seemed to stay tighter in the bull at every shot.
I agree with Oldgoat, at least in my experiment the back end of the arrow being lighter allows it to correct faster. The forward weight/momentum will carry it through.
And that's even more important during the extreme deceleration at impact. ANY amount of deflection or off-center forces at impact are greatly magnified the more aft weighted the arrow is, significantly effecting penetration. Plus a higher FOC arrow HAS to be stiffer to shoot well, which also means it will flex less at impact, again transferring the force more directly down the shaft, increasing penetration.
Those having trouble tuning a high FOC arrow are likely not able to find a shaft stiff enough to tune. That's the real challenge of shooting EFOC out of a compound.
"Do it again with a 4 foot long, 600 grain pole and put 50% of that weight on the tip. which end is going to hit the ground first?"
Obviously, the weighted end will. But that's because the center of gravity is nearer one end, which means there is more surface area from the center of gravity to the lighter end, creating more drag. This effect is negligible in arrow flight since the increase in FOC from "normal" to high is not that significant, you already have a high surface area on the back of the arrow in any case (and you can use less the higher the FOC), and the vertical component of arrow flight at normal shot distances is negligible. The positive effects of getting the most FOC you can tune, far outweigh any trajectory increase.
Umm... NO
It doesn't matter where the weight is. If you weight the back of an arrow to get the weight "BOC", then what you have done is weaken the dynamic spine. That is what would cause the arrow to deflect and have poor penetration.
I'll say this real slow so everyone can understand... All else equal (arrow weight, dynamic spine, arrow length, broadhead, arrow material, and speed) It doesn't matter where the weight is... if the arrow is flying straight and true, the penetration will be the same.
Nobody can disprove that!
740 gr arrow @ 174fps ...... It has 49.7 ft-lb KE
350 gr arrow @ 368 fps h....... It has 104.7 ft-lb KE
Do you really think that an arrow with about 50 foot-pounds of KE will have the same penetration as one with about 105 foot-pounds of KE, even though they have the same momentum ?
"KE is what moves the arrow, not momentum. Energy is what starts the arrow moving and the dissipation of that energy is what stops it. If momentum was truly a factor in penetration, it wouldn't matter whether the momentum came from velocity or mass. Look at these two combinations of weight and velocity that produce EQUAL amounts of momentum : 740 gr arrow @ 174fps ...... It has 49.7 ft-lb KE
350 gr arrow @ 368 fps h....... It has 104.7 ft-lb KE
Do you really think that an arrow with about 50 foot-pounds of KE will have the same penetration as one with about 105 foot-pounds of KE, even though they have the same momentum ? "
Umm... I think you posted on the wrong thread. This is not a KE vs. Momentum debate.
"It doesn't matter where the weight is. If you weight the back of an arrow to get the weight "BOC", then what you have done is weaken the dynamic spine. That is what would cause the arrow to deflect and have poor penetration."
Apparently, it does matter where the weight is otherwise the above statement would happen. Weight forward is what will contribute to driving in deeper, and not effectively deflect the arrow, as I said. Otherwise, just glue two Gillette razor blades to the side of an arrow at the front with a micro-lite tapered tip and put some lead weights evenly spaced on the inside of the shaft and see what happens.
I will agree with you, however, this is not a debate about KE vs p. The only time that argument even makes sense is when you look at the delta KE and p with SAME arrow of mass at varying velocities because that is exactly what you are dealing with in a system. KE decreases at a faster rate than p, so clearly, it is an invalid argument to make that it is a predictor of penetration...IT SLOWS DOWN AT THE SQUARE OF ITS VELOCITY AND IS A FUNCTION (OR RESULT) OF MOMENTUM.
As to the original question: an FOC above 12% in a hunting situation is a very, very good thing.
Sorry, but no arrow is "steered" from anywhere.
"I'll say this real slow so everyone can understand... All else equal (arrow weight, dynamic spine, arrow length, broadhead, arrow material, and speed) It doesn't matter where the weight is... if the arrow is flying straight and true, the penetration will be the same."
Unfortunately, for some, no matter how slowly you say anything that's true, it likely won't be absorbed.
Folks, x-man is correct - weight is weight. EFOC/UEFOC/YOMOMMAFOC/WHATEVERFOC is a means to weight an arrow......That's all it is. Arrow weight plays a role in penetration, but there's tradeoffs everywhere you look.
But to properly set up an arrow with high FOC everything else WON'T be equal. It's the quantitative effect of Higher FOC that makes the difference so significant. Also, what dynamic spine? That is measured by where the force is applied - normally at launch. Dynamic spine at impact is vastly different and will have a measured affect on penetration.
All of that weight on the front.....has to be launched from the back.
Thats why I say in my testing it was very critical...a very small window of what flies well and what doesn't. Then add a form flaw and a BH...like on the shot of a lifetime- grin......and its asking for bad arrow flight.
I thought the force of gravity was constant? It didn't know where the center of gravity is by theory? That weight is weight. Besides, aren't we discussing how gravity, influenced by weight distribution, affects the trajectory of an arrow? If the weighted end hits first and, it will, the same thing will happen with an EFOC arrow versus one that has the weight more evenly distributed, launched from the same bow. I understand at close ranges that is negligible. Out of a trad bow, 45 yards isn't close and, the differences are a couple feet for my 58 through 76 pound bows, drawn 28.25 inches. God Bless
Maybe I'm just smart enough to figure it out? I don't know
And I bowhunt. What "oly" shooters shoot is no concern to me. They could not care less about penetration brought bone or tissue.
That's what I care about. I also shoot "normal" foc and do ok as well
But hey if it works for you. I also learned recently that a 44# recurve with a 500 grain arrow is "more than enough for anything in North America". Learn something different every time I open up the interwebs. And I also learned you can shoot doe in the shoulder with a 66# recurve and 2219 and not have enough. Bet that guy wishes he was shooting 44# and 500 grains. Maybe he didn't read the same thread I did.
Now I'm no mechanical engineer or physicist but I can figure out how gravity works simply from my simple experiment.
Science!
"....if the arrow is flying straight and true, the momentum will carry it through the same. Nobody can disprove that!"
I merely disproved that part of his post. Rather than giving a rebutal he instead deletes that part of his post and then has the gall to accuses me of changing the topic. Very small of you, x-man.
Where the weight is located can matter. There are pros and cons both ways.
The further back weight is located, the less the arrow will flex at launch and the more it will flex at impact. The quicker it stops, like when hitting bone, the more it will flex. The more it flexes at impact, the greater the loss of energy that could have been used for penetration.
With the weight more up front, the arrow will flex more during the acceleration of the launch, with a large broadhead this could mean accuracy problems.
Now you are arguing just for the sake of arguing.
I edited my post because I am not trying to confuse this debate with a different one. KE vs. Momentum has absolutely nothing to do with this thread. My original post and follow up post has not been deleted in any way shape or form. The issue here is EFOC, not the difference between KE and Momentum.
You have spent the last several years stalking me to try to find flaws in my posts. It's getting old pal. Time to let it go. Whatever I did to you in the past????? just let it go.
And BTW, when you quote someone, make sure you are correct. The line in your quotation marks above is not correct, what my line first said was this. " ...if the arrow is flying straight, the momentum will carry it through." If you have to guess at what I said, don't put it in quotation marks, please.
You edited it by deleting part of it, just as I have shown. You are getting even smaller.
So if your shooting a 29 inch arrow it has the same stiffness as a 26 inch arrow. So lets say the combined inserts weigh 200 grains plus a 100 grain BH. This is not the same as screwing on a 300 grain BH on a 29 inch arrow. The spine will be weakened.
Just something to consider if your building high EFOC arrows when it comes to spine.
Purdue, that is called an untuned arrow built by someone who has no idea what they're doing
And I have since put it back just to make you happy. Now there is nothing missing. It still doesn't change the fact that you are changing the subject. Do you have a viable comment on disproving my post? Or will you continue to make this a vocabulary issue. Your only contribution was to claim that KE is what I should have had in my post instead of Momentum. I'm not going to get into that argument on this thread. So to please you let me edit my statement to this...
... All else equal (arrow weight, dynamic spine, arrow length, broadhead, arrow material, and speed) It doesn't matter where the weight is... if the arrow is flying straight and true, the KE will carry it through the same weather the arrow is 15% FOC or 30% FOC.
What's the KE when an arrow gets 3" into an animal? A hell of slot less then when it left he bow and when the arrow stops on bone well your KE equation just turned into a " must have hit the shoulder ridge"
You guys are better than the funny papers
Of course it is. But the arrow is not falling in a vacuum. It falls through air which creates drag. And there will be more drag, since there is more surface area, at the lighter end. The arrow will begin to rotate around its center of gravity ending up, eventually, pointing straight down, heavy end first.
"And the one with the FOC will land the exact same way as the one with no point. Flat."
Well, not quite. At the distance of a few feet, you may not notice the difference, and that's why a higher FOC arrow doesn't "nose dive" when it's shot. The vertical component of its trajectory is only a couple of feet, even with a heavy arrow traveling relatively slowly over 40 - 50 yards. Drop them the same way from 50 feet high and you will see the higher FOC arrow start to stabilize nose down more quickly than the lower FOC one.
What if you remove the fletching, and use only field points. Will the higher FOC arrow still fall nose first quicker than the lower FOC arrow?
To all those that say where the weight is doesn't matter in arrow trajectory remember this. If trajectory wasn't affected by FOC, flight shooters wouldn't care about getting their arrows balanced. God Bless men.
http://second-opinions.ginwiz.com/lnk000/=www.second-opinions.co.uk/flight-arrows.html/
"In an attempt to resolve the debate, an American engineer and archer, Dr Clarence Hickman, conducted a series of experiments in the 1930s with a hollow metal arrow. Dr Hickman fitted a moveable weight inside the shaft which allowed him to vary the arrow's CofG without changing its overall weight. The arrow was shot using an 11 kg (24 lb) bow mounted at 45E in shooting machine. The results he achieved showed clearly the advantage to be gained from having the CofG forward. He tried seven CofG positions from 32%, to 57% of the length of the arrow, together with six sizes of fletch ranging from 100 x 25 mm to 15 x 10 mm. With all fletch sizes, distance fell slightly as the CofG moved backwards. With the CofG behind the centre of the arrow, the distances achieved fell markedly. The greatest distance he achieved was with the CofG at 32% and the arrow unfletched. On a 15 inch carbon Flight arrow, I try for a CofG about an inch in front of centre which is 43%. It is difficult to get the CofG much further forward as to do so would require too heavy a point, making the overall weight too much. "
We could argue this until the end of time. I'm not going to do that. I have just listened to guys say that where the weight is located on an arrow does not affect the trajectory. And, that is simply incorrect. A front heavy arrow versus a more balanced arrow of the same wight will shoot lower at some point. God Bless
By my calculations on what is modern AMO FOC that comes out to be about 6.6% FOC? Not even 10% which I hear many say is good enough FOC, most shaft manufacturers recommend 10 to 15%.
"It is difficult to get the CofG much further forward as to do so would require too heavy a point, making the overall weight too much. "
That should be noted as well.
Again, I know a few crack shots that are shooting golf balls at 40 yards with <10% FOC. EFOC has no effect on modern compound archery other than destroying downrange trajectory with needlessly heavy arrows.
In nearly every case, in order to obtain EFOC the finished product is heavier, sometimes MUCH heavier than what the archer was shooting prior. Heavier heads, inserts, etc require much heavier spines out of relatively high performance compounds, corresponding heavier shafts as well. IF you can even get shafts readily that are stiff enough to tune. Many times have to start going to footed shafts to help spine, more and more weight. It's this cycle EFOC brings to the game.
That anyone would be surprised that the heavier arrow they just created had better terminal performance is, well... surprising. Of course it does. That the increased performance can be directly attributed to EFOC is very debatable. Only if the arrow was not impacting straight enough, as a unit, would it even be arguable.
As for two equal shafts dropped flat, one with high EFOC and the other not from 3 feet. Most likely the EFOC would end would hit first you just couldn't see it in such a short fall. However drop them both flat in some thick mud side by side and tell me what you find out. Im betting the EFOC side/end sinks deeper as the lighter shaft will be simply sitting on top.
While that is true, time of fight, out of a particular bow, is determined by weight and drag. If you put enough time into developing your set-up, you can use less fletching the higher the FOC, and therefore less drag (and better x-wind performance as a by product), positively effecting trajectory (if you can keep overall weight constant).
"...fly like a laser !!"
Whenever I see that type of statement, it indicates too much emphasis on speed/trajectory when other factors are so much more important in a HUNTING arrow.
...uh....IF all you prefer to have is 10-15%.
30+% is better than good if you know what you're doing when building bow bullets
Seriously bro that was the funniest stuff I've read in a long time
Seriously bro that was the funniest stuff I've read in a long time
You out physic'd the supposed physics pros!
Shooting machines, missile tests..... hang a lot of weight on the end of an arrow and then shoot it under hunting conditions.You getting perfect flight then?
I've played with EFOC over 30%....and sure I could get it to work under perfect conditions...but it made the setup more critical of form errors and such...how could it NOT be more critical? Its a waste of energy trying to talk common sense to some of you guys.
Easton recommends 8-15% FOC or close to it.....of course Easton has NO CLUE what they are talking about, they've only been working with engineers that specialize in archery and making these arrows before many guys here were born. /sarc
The arrows I'm using now are just under 17% FOC and I see no reason to consider changing unless I intend to hunt much larger dangerous game than the deer I chase. I get a good balance of trajectory and penetration.
x-man, to answer your question about what happens when you remove the fletching - there was a thread on the Leatherwall where changes to javelins were made to ensure the point stuck rather than the javelin hitting flat. They moved the weight a bit forward to accomplish that by causing the point to drop first. The result was distances dropped also.
I hope that wasn't meant towards me? I have not once mentioned trajectory. I have been addressing the folks who seem to think EFOC helps penetration, which it clearly does not.
EFOC can and will affect arrow trajectory for sure, but probably not a measurable amount at realistic hunting yardages.
I only read the first two sentences of the article Purdue copied and pasted. I spit out my soup laughing too hard. ;) The 1930's??? really??? a movable weight inside the arrow??? really??? how does that keep all other parameters constant??? how do you know what is being tested??? How did such a farce get published???
I knew the answer, I was just trying to get him to expound on it some more. I have read many articles on javelin flight as well, which prompted me to ask.
I hate to type, so I keep my posts as short and to the point as possible. I wish my computer had the technology for me to talk into it, and it would type for me. :)
"Again, I know a few crack shots that are shooting golf balls at 40 yards with <10% FOC."
Try that with a BH under HUNTING conditions if you want to shoot a set-up very critical of form.
"EFOC has no effect on modern compound archery other than destroying downrange trajectory with needlessly heavy arrows."
That's just a matter opinion, and one not supported by the physics nor testing, nor many other's observations and experiences.
"Only if the arrow was not impacting straight enough, as a unit, would it even be arguable."
Virtually EVERY shot into game is deflected at impact to some extent due to each blade hitting different density tissue or striking the hide at an angle, whether or not the arrow is flying straight at impact. So, at the very least it's arguable in every case.
Again though, I agree that by definition Efoc is nearly impossible to achieve, and tune, for a compound bow, because of the difficulty of obtaining a stiff enough shaft, and the fact that the finished arrow is heavier than desired by most hunters. But getting the most you can by choosing a heavier BH (certainly more than 100 gr., unless other weight is added) and not using any more weight than necessary on the nock end, is valid for improving not only terminal performance, but overall arrow stability and x-wind performance.
Aim for FOC between 10%-15% and get all the other aspects correct (tuning, quality components, and tune the shooter), and you will be fine.
You never know what rabbit hole you will end up in....grin
