Foc????

[Okiehunter]

What is the best FOC for a hunting arrow?

I am tinkering around with new Black Eagle Carnivore's.

With a 100 gr point I am at 315 grains total and a FOC of 14.16%

With a 85 gr point I am at 300 grains total and a FOC of 12.52%.

Which is best??

[bphillips]

The higher the better


Not sure what spine you're using or what setup but I wish I could get mine up that easy. I have to add lots of weight up front to a .250 spine just to get 16-17% spined right for me in a hunting arrow but I would like to get around 20%.

[Okiehunter]

To add more detail I brought out the chronograph. Arrows are 25.75 inches, 400, with 3-2” Blazers shooting from a Z7 at about 62 pounds.

With a 100 gr point I am at 315 grains total, a FOC of 14.16% at an average of 284 FPS with a kinetic energy of about 56.43 ft-lbs.

With a 85 gr point I am at 300 grains total and a FOC of 12.52% at an average of 293 FPS with a kinetic energy of about 57.20 ft-lbs.

Higher FOC with the 100 grain tip but higher kinetic with the lighter faster arrow.

Which is best??

[bphillips]

To add more detail I brought out the chronograph. Arrows are 25.75 inches, 400, with 3-2” Blazers shooting from a Z7 at about 62 pounds.

With a 100 gr point I am at 315 grains total, a FOC of 14.16% at an average of 284 FPS with a kinetic energy of about 56.43 ft-lbs.

With a 85 gr point I am at 300 grains total and a FOC of 12.52% at an average of 293 FPS with a kinetic energy of about 57.20 ft-lbs.

Higher FOC with the 100 grain tip but higher kinetic with the lighter faster arrow.

Which is best??

There is more KE but momentum is what matters and it is higher with the 100gr.. That being said there is so little difference in the two it shouldn't matter. I would go with the 100 personally because the drop won't even be much of a difference. To see any real difference you would have to have a good amount more than 15gr between the two setups.

[muddyfuzzy]

lose the blazers, switch to feathers and you will gain around 1% foc on either set-up. you'll get higher foc and better steering, you could even switch to a 125 grain head and gain another 1.5% on over the 100 grain head.

[Mudslinger]

IMHO, the higher the FOC, the higher the weight of the arrow, the better everything will be. I am talking about more forgiveness and more accuracy at longer distances and a definitley quieter bow. KE should really be taken out of teh bowhunting world and have everyone look at MOMENTUM. MOMENTUM is the ability of the arrow to penetrate and that is what we are all after, penetration right!

Either of your set ups will work, there is too little difference in weight to matter. there is a point that too much weight will not help, but I added 150 grains to the front of my arrow set up for more FOC, 19%, 410 grains to 560 grains and my KE still went up by 1 but my MOMENTUM factor went way, way up! A plus on every front.

[Okiehunter]

How do you measure momentum? Or can you?

[JW]

I shoot 13%. But my main target is whitetails. Not high but not low. Big animals im a fan of that 20% mark.

Same bow and arrows but with swapping points and getting my FOC below 10 i saw my long range groups open up vs the 13%.

[Caprock]

do you measure to the end of the insert or to the end of the point?

[12RingKing]

I like momentum as a unit of measure better than KE too.

Momentum was explained to me as the arrows ability to drive after initial contact.

[Mudslinger]

Here are your formulas for KE and Momentum.

http://archeryreport.com/2009/11/arrow-kinetic-energy-momentum-archer/

[enewman]

I agree with the momentum statement. Right now I'm playing with broadheads in the 175 to 300 gn range. Working my way up to around 24 foc. Here's the question. There are charts for how much kinetic you need for a size of animal. So how much momentum do you need. I think DR Ashby talks about .57 but all his test are on Africa animals.

[JW]

I agree with the momentum statement. Right now I'm playing with broadheads in the 175 to 300 gn range. Working my way up to around 24 foc. Here's the question. There are charts for how much kinetic you need for a size of animal. So how much momentum do you need. I think DR Ashby talks about .57 but all his test are on Africa animals.

On whitetails, black bear and such dint worry about. Shoot the sucker then dig it outta the dirt after the pass thru.

Im a firm believer in Dr. A's work,,,, for great big critters.

[muddyfuzzy]

I think DR Ashby talks about .57 but all his test are on Africa animals.

this is true, but several species similar in size and toughness to na game were in the results as well. its really something every bowhunter should read.

[JW]

this is true, but several species similar in size and toughness to na game were in the results as well. its really something every bowhunter should read.

NA game are runts to penetrate compared to a most African game. Hell i saw a guy put a junky rage thru a Bison on TV the other day. 350 grain total arrow weight and a 70 pound hoyt. Boit the only critter i build my heavy arrows and monster foc for is great big boars.