My arrows are 31" from point of tip to back of nock.
Tha balance point is 11.5 on the front 19.5" on the back they weigh 610 to 615 grains

How do I figure my foc percentage?

Kris

You've got a measure'n stick...all you need now is a calculadder. (or a writing stick).

...or just type it in here.


  Jackson\\'s Archery  FOC by Measurements  

To get back to the homepage you may have to type "jackson archery" in google.

Foc is 12.9 - say 13

Soilarch,
Thanks according to the link you gave me I got 13.1 FOC

measuring from tip to nock groove I got 30 7/8 and the difference from center to balance is 4 1/16

Is this good FOC? And at what point does it become EFOC?

EFOC as outlined by Dr. Ashby is 18%+.  With a 31" arrow you would need to have a balance point at or in front of 5 5/8" FOC.

folks, please remember to check the 'how to - resources' forum!

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Here's a link to an Excel file I built that'll give ya FOC and GPP ...

Excel .xls file

Enterprise Excel .xlsx file

   

check out gold tip arrows website

Sticks, 13% is fine. The "right" FOC is a topic not many agree on.  It won't hurt you to go higher, and I personally wouldn't go any lower, but 13 is a good solid number many here have been shooting for years and years.

The main thing is getting the arrow to fly well, if they're doing that take some advice from an incurable tinkerer (me)..."Go shoot some arrows and enjoy it for awhile before you go pulling yer hair out about how to raise FOC."

13 is fine.  The thing that really hooked me on traditional archery is that there is no one right way, or even one "best" way.  We all get to do our own thing and find out what works for us.


*IF* the arrow flies well, 13 will put deer, elk, and small dinosaurs on the dinner table.


P.S. You'll probably need more than draw weight for dinosaurs...or so I've heard.

If you place the arrow on your out stretched index finger at it's center and it tips gracefully forward,,that's about right.

If it flips over,falls off your finger an stabs you in the foot,,,that's a bit too much.

imo, if the arrow flies well, is of decent weight, the trad broadhead is really sharp, and you know how to hit the spot consistently, yer good to go.  'nuff said.

however ... there's absolutely Nothing at all wrong with piling on the arrow and/or front end weight if that works for you, too.  

righteous foc is an advantage for flight tracking - that's been proven too many times over for decades and there is minimum foc one should strive for with a hunting arrow.  whether or not it helps with penetration is your guess and the results of your personal testing.

Rob neat calculator you put together
thanks for pointing it out.

Sticks....yeah 13 is good, and with good tuning and arrow flight, you can kill anything you want on this continent with that arrow and its 13% FOC ALL DAY LONG. As Rob pointed out, you gotta have some FOC obviously to steer the arrow, and I've always gone by 12% for bheads as the minimum and 15 better for all around hunting situations/positions.weather.  15 is just a bit insurance, and I ended up with 18% for years based on the Bhead I chose.  That's what *I've* found, and others may fine something that works best for them. So, you have to have some FOC for the arrow will track and the Bhead will drive....13% puts you there.

Remember, tuning to perfect arrow flight, a properly sharpened head, and your shooting ability are WAY more important that some 'exact' FOC number.

1) Get your arrows accurate by you, 2) get them flying perfect to the target, 3) then get the head properly sharpened.  That's the basics and bowhunting's 1-2-3 on the hunting preparation side.  This, along with improving your hunting skills in the field,  will kill WAY more animals that all the peripheral static.  

They don't call them 'The Basics' for nothing....and another word for basics is Foundation.  Pretty light switches and hand rails don't mean nothing if the foundation is crumbling.

I went to trad for the simplicity of it and like it that way for sure.

I came by by this set up because I got my new Slapstyk and wanted to shoot a heavier broadhead than I have in the past. I came to that conclusion from reading post here. I never intended to pick it apart but after going to a 190 up front from 125 and getting my arrows tuned thanks to Rick at The Feathered Shaft I ended up with this setup.
48# @ 27.5" shooting a 29" tapered shaft 190 up front for a total arrow weight of 610 - 615 grains.
I was amazed at the flight and impact of the arrow. These babies thump when they hit more so than any set up I've shot in the past.

I'm not looking to pick it apart or make it better cause I have good flight and am satisfied with the setup but once I arrived at this destination I got curious about what I had percentage wise and all that mumbo jumbo.

Thanks for all the help guys    

I ain't gonna be one to chase after EFOC but am definetley a believer in FOC for sure. I think from here on out I will stick to around 13 to 15 percent and call it good.

QuoteOriginally posted by Stiks-n-Strings:
I went to trad for the simplicity of it and like it that way for sure.

.....I never intended to pick it apart

.... I was amazed at the flight and impact of the arrow. These babies thump when they hit more so than any set up I've shot in the past.

That's one of the unique aspects of traditional archery: you can make it as simple or as complex as you want it to be.

To me, the tinkering is a lot of fun. If you had never taken it upon yourself to "pick it apart" you wouldn't have found a new arrow that gave you flight and terminal performance that exceeded your current setup.

If your stand-by stuff works that's great...but there is absolutely nothing wrong with experimenting and tinkering to try something new or different. It doesn't make you any more or less "trad" and certainly shouldn't be looked down on...it should be encouraged.

Keep tinkering...keep trying new things...you may find something you didn't expect and learn something you didn't already know.

Good post JC, exactly...yes, you have to 'tinker' to get the proper arrow flying...no doubt about that....and that's also 'the basics' and no one should look down on the basics or foundation which again arrow flight is a huge part of....achieving proper arrow flight is paramount, and you have to trial an error to get there.

I hunted with 13% foc arrows out of my compound for 20 years and killed lots of animals.  They will kill lots of animals out of a trad bow to.  I have to say though that theoretically there is no such thing as to much foc.  Bullets fly so well because all their weight is in a tiny little piece of metal.  

I have arrows tuned to UEFOC and they weigh in at 584 grains out a 55 lb bow.  They work great for me are pulling in at 10.6 gpp of draw weight and fly like bullets.

It is far more important to find an arrow that works with your bow and spend your time tuning that arrow than it is to chase foc.  Foc is the icing on the trad cake for those who choose to pursue it.

Good luck and great hunting.  Your arrows will put plenty of meat on the ground for you.

All Right guys, now you got me wanting to pick a little. LOL

My arrows  are spined at 65-70 and are shooting great where I'm at. My question is if I take off an inch, How much does that stiffen my spine and how much weight will I have to add to the front to keep it shooting right.

I have an internal footing jig and can add a piece of brass rod internally to up the weight.

The only way to know is to try it but I have fooled around with several bows drawing 50 to 55 lbs and found I needed to add 15 to 18 grs point weight when going from 30" down to 29".The 50# bow took 15 grs,the 55 # bow took 18 grs.I would try 25 grs but have no idea if your results will be the same.

For me it seems to require 25-30 grains more in the head to shorten the arrow an inch.

when it comes to free form aiming sports like archery, we're all 'experiments of one' and how archery tackle hardware works for ya depends a lot on you, the shooter.  take all of this tech rap stuff with a shaker of salt and do yer own testing if ya wanna know what works best for you, not me, and surely not them.  

for the relative newbies out there, i recommend not biting off more than you can swallow let alone chew.  get yer trad archery foundation built on solid ground first, before playing with gear tweaks.