Theory, you can guess but it must be tested.

[vermonster13]

The high FOC shaft should be thinner and have less drag when using a brass insert and same broadhead to make weights match.

[Widowbender]

I'm glad deer can't read...   :D

[ron w]

I just don't want to think this much....lol.

[Ragnarok Forge]

I will be interested to find out what the real world testing says.  Let me kow if no one else plans to test this.  I am building a firing system for testing the speed differences between skinny and fat strings.  I could always work up some arrows for standard, high, and extreme FOC and test them at various yardages to see if there is a difference in drop off.  

I have to agree with the earlier posts that point out that physics says the extreme FOC should fly the flattest.  They recover more quickly and fly truer to the target, thus loosing less energy to shaft modulation.

Anyways, let me know if I need to add this to my list of testing to do.  Note with hunting season starting in a week it will be winter before I start the testing.

[Ben Maher]

for those few of us who shoot Hill bows the curvature of the earth also needs to be taken into account. Regardless of FOC, EFOC, PMS, etc., when an arrow is shot parallel to the earth from a Hill bow it takes days for it to hit the ground. Takes even longer if you shoot from the east towards the west.
           
Tom , only Hill shooters understand the truth !!!

Ben...[Physics deprived Hill shooter ]....

[Jim now in Kentucky]

An efoc arrow will  have less mass behind the point/weight, which normally would mean the shaft would be less stiff. That would mean the shaft would actually bend more and recover more slowly than a more standard arrow. But the lighter shaft behind the heavier head/weight would indeed stabilize somewhat quicker because the wind force on the side of the feathers could more easily move the smaller mass back in line with the arrow's flight.

Inertia and momentum are the same for both arrows because they have the same mass. Placement of the mass has nothing to do with these forces.

The efoc arrow would nose down faster if the arrows were simply dropped in a horizontal position from a great enough height to allow nosing down--say 20 or 30 feet. But flying at 160 fps, the drop is so small in comparison to the forward motion that the difference would probably be immeasurably small.

Most of what is reported these days though does seem to favor the very foc weight distribution.

I know I don't shoot well enough to notice a difference!

Jim Davis

[JimB]

OL says the perfect arrow would have 100 % of the weight up front.

I would think you would need arrows of identical material and diameter to make a fair comparison.With this,it would be hard to come up with 2 that would have the same overall weight because one would have to have more point weight,thus you have to start with a stiffer static spined shaft and it would be heavier as would it'd head.You lower FOC arrow and higher FOC arrow would always be different in overall weight(I think).I have played with this a little with 2016's+2018's and 55/75's + 75/95's and that's the way it always plays out.

You might be able to make one arrow aluminum and one carbon but of the same diameter,fletch,etc and have them come out the same overall weight? That would take some brainstorming and my head is hurting already.

I understand it's very hard to get 30-35 % FOC unless the bow has vertually no shelf or sight window(way far from center cut)and then very weak,light shafts with a lot of point weight.

[amar911]

I think the theory of relativity applies here. If it is me or my relative who is shooting the arrow, we will claim it did not drop as fast. If the person shooting the arrow is not a relative, then we will claim that arrow dropped faster. Gravity also comes into play. The gravity of the harm done by cheating for my relatives is much less than the gravity of the harm created by someone else cheating for his relatives. I hope all of you now understand relativity and gravity and their impact on the drop of arrows.        

Actually, an 26% EFOC arrow has been conclusively and scientifically determined to drop half the width of a gnat's eyelash less at 90 meters than an otherwise identical arrow that has a 11% FOC. The testing was conducted in climate controlled governmental installations within Cheyenne Mountain and corrected for temperature, altitude, humidity and every other variable factor, all in accordance with ASTM 30-2804.157(B)(3)(g)(iii), the most stringent scientific engineering standard for flight testing of arrows from traditional bows.

Allan

[amar911]

Grammatical errors corrected:

I think the theory of relativity applies here. If it is me or my relative who is shooting the arrow, we will claim it did not drop as fast. If the person shooting the arrow is not a relative, then we will claim that arrow dropped faster. Gravity also comes into play. The gravity of the harm done by cheating for my relatives is much less than the gravity of the harm created by someone else cheating for his relatives. I hope all of you now understand relativity and gravity and their impact on the drop of arrows. [readit] [knothead]

Actually, a 26% EFOC arrow has been conclusively and scientifically determined to drop half the width of a gnat's eyelash less at 90 meters than an otherwise identical arrow that is 11% FOC. The testing was conducted in climate controlled governmental installations within Cheyenne Mountain and corrected for temperature, altitude, humidity and every other variable factor, all in accordance with ASTM 30-2804.157(B)(3)(g)(iii), the most stringent scientific engineering standard for flight testing of arrows from traditional bows.

Allan

[elkbreath]

I am in no position to test it, though I'd like to see it, though I'm pretty sure amar911  is right!        

IMO
The portion of the arrow with more mass will hold more energy, thus staying truer to its course than the low mass portion its dragging greatly stabilizing flight.  In the instance of EFOC, the more of the mass that is located in the very front the more stable will be the flight and the more efficient the energy stored will be used.  If that mass is in the rear, the arrow will want to jackknife, with it in the front the rear portion is smoothly drug.

The EFOC will also retain its energy longer as its is stored in a smaller area, giving stable flight for a further distance than the one with it's mass spread out.  Eventually the front will indeed dive , but that time of final instability will have been reached a significant distance after the arrow with homogeneous mass gave out.  This is precisely the reason OL's flight records are broken, and the same thing that will cause this test to be moot.  

 Moot because, though it did indeed dive it reaches that point long after its brother who didn't dive had already died.  


     

[p1choco]

It's possible to have same diameter shafts, same lengths in different spine to work right with heavy and light heads respectively.  Using thin rope or plastic tubing could make up the weight difference in the lighter arrow keeping the weight and diameter equal.  It might take a lot of experimenting to get it right though.  I'm still interested to see how George's arrows fly regardless of the other variables.

[Scott F]

George,

If you consider a javelin to be a really long arrow without fletching you'll have your answer.  People began throwing javelins out of the stadiums - literally.  The answer was to move the weight forward, closer to the tip.  

Your from PA where they still throw these in high school, go and ask some track coaches what their old records used to be prior to moving the plug forward.  I bet that you will be surprized.

Scott

[Biggie Hoffman]

3 pages so far... I bet George is blowing coffee thru his nose this morning.

[Art B]

Obvious you guys don't shoot large 5 1/2" to 6" fletched arrows "around" your handle. Sorry, this topic may not apply to use primitive types.  

[James Wrenn]

Should be easy enough to test without a machine if you use a bow with sight pins.A centershot compound would be easy because you will have less effect with spine changes when loading the arrows for weight.If it was not raining here today I would test it for you.  

[Jeff Strubberg]

Equal weight means equal effect from gravity.   The only thing that could cause the EFOC arrow to drop faster would be drag from the shaft not being parallel to the direction of travel.  

I'm betting the drag effect s so slight it's hard to even measure (given the diameter of an arrow shaft), and disappears completely with fletching.

[Don Stokes]

Yesterday I was shooting my 50# Super Kodiak at 70 yards (aiming with the point) with arrows from two sets. One set (5) weighed around 580 grains, and the other set (2) weighed around 670 grains. Theory tells us that the heavier arrows would drop out first. They didn't, in several trials. 5 of 7 in my last group would have fit in the mouth of a 5 gallon bucket. One of each set was outside the group, low.

That has nothing to do with the subject at hand, but it shows you where theory can lead...

I remember reading about a similar FOC test from "Archery- The Technical Side". An aluminum arrow was made with a sliding weight, and no fletching. It was shot with the weight in different positions from extreme foc to reverse foc (boc?). As long as the weight was at the middle or forward, it seemed to make no difference in cast. Too far back and it would tumble. Drag was the same, since it was the same arrow. This test could be done in a similar fashion using a finished aluminum arrow with a positionable weight inside it, to eliminate the variable of having two different arrows with different fletching, points, etc.

I might try it, but I don't have any tubular arrows.  

[limbow]

It's Monday, I have read this thread 3 times now and I am still smiling and laughing! What a way to start the work week, thanks for the thread George.

Allan, you are hilarious!  

[Fletcher]

George, I'll take on your question.  I want to know this for myself anyway and have been setting aside some fir shafts to test with.  It's gonna take a while to get things set up but I'll keep you all informed as I progress.  The likely test bow will be a Griffin Tsunami set up with a sight and a clicker.

Sorry, Tom.

Rick

[Tom Mussatto]

Originally posted by Fletcher:
George, I'll take on your question.  I want to know this for myself anyway and have been setting aside some fir shafts to test with.  It's gonna take a while to get things set up but I'll keep you all informed as I progress.  The likely test bow will be a Griffin Tsunami set up with a sight and a clicker.

Sorry, Tom.

Rick

My hero's of the past are dropping like flies.

Time for me to go back under my rock????