What's your FOC?

[Norteno]

I shoot a 27-5/8" 400 spine Easton FMJ (10.2 gpi) drawing 60 lbs.
I went to this heavier arrow as I prepare for the upcoming Elk season. I am trying out some 125gr field tips trying to determine if I get better flight with a higher FOC. As of now I'm just noticing a slight lower impact point at 50yds. I've been shooting like crap the last two days since I just got back from a ton of business travel the last three weeks so other than that can't say I'm grouping better.

I've read your FOC should be between 7-15% for hunting. Here is where I am at and why I'm trying out heavier tips. My total arrow weight is getting a little heavier than I wanted to though.

What is your Front of Center (FOC) that works for you.

FOC: 7.9% @ 436gr w/100gr tip
FOC: 10.5% @ 461gr w/125gr tip

[bigorange]

Haven't measured and calculated my FOC but I need to. I recently switched from 100 to 125gr heads and noticed a significant improvement especially at longer range.

[nlacost]

you just made a 400 spine arrow basically a 500 by putting that heavy head on there...stick with 100 grains..I use 300 spine Victory armor piercing arrows and FOC around 13...with the 50 grain insert and 100 grain head..

[JACK]

You know when you add weight to the front of your arrow it weakens the spine...There is a little more to it than just changing tip weight...

 

Currently shooting VAP 250s...682 grains @ 24% FOC

[4Falls]

Interesting info. I am planning on shooting 100 gr G5 expandable heads for August deer then moving up to 125 grave diggers for my November elk hunt. Maybe ill rethink again... and again.

[Shedhunteraz]

you just made a 400 spine arrow basically a 500 by putting that heavy head on there...stick with 100 grains..I use 300 spine Victory armor piercing arrows and FOC around 13...with the 50 grain insert and 100 grain head..

This is a great set up.

[120carp]

.340 spine Axis with 100 gr head mine is 10.5% with the regular components.

[4Falls]

Using an online FOC calc, I'm at 10.5%. Maybe increased tip weight may be a good idea after all. Imay screw on a 125 at the range tonite and se how she flies.

 

28 1/2" axis 300's 72# Hoyt Vulcan

[TOBY]

not to shift direction of this thread,but you guys shooting the heavy weights should run your set-up thru a kinetic energy chart. Heavier is not always better. There is a spot between toothpick and lincoln logs that is the best for each individual set-up. Chrono your arrow and use this...http://www.goldtip.com/calculators.aspx

There is also a FOC chart below it.

[Norteno]

you just made a 400 spine arrow basically a 500 by putting that heavy head on there...stick with 100 grains..I use 300 spine Victory armor piercing arrows and FOC around 13...with the 50 grain insert and 100 grain head..

Every chart I've looked at shows my draw weight and length falling at a 400 spine arrow. That is both with a 100gr and 125gr tip. Even if I bump it up a little bit for a faster bow I'm still at 400. I'm experimenting because I wasn't too comfortable being on the low end of the 7-15% range. From the responses here sounds like most of you experienced guys have an FOC in the mid to high range.

[trphyhntr]

that feel when, don't know what FOC is.

[AverageJoe]

Dont get too worried with FOC. Just keep it in the normal range and you will be fine. You can bump it up higher to make you feel better but it isnt needed. If you want to its fine but just dont fall into the way of thinking that you need extreme FOC to kill an animal when in reality your current setup at 7.9 is fine and will penetrate even an elk with no problem.

[Guest oneshot]

hehehe TrphyHntr...

I shoot a BW recurve, 49lbs@ 30inches, GT expedition carbons, feather flechings and full length 30inch arrows and my FOC is at 14% right now (I am at the lower end of overall arrow weight)(want to go higher) with 100gr Muzzy b'heads, alot of stick bow shooters have higher FOC's(check-out the monster 250-300gr. b'heads stick-bow shooters have on the ends of their arrows) then wheelie bows to get better penetration with the lower poundage they shoot, wheelie shooters seem to be stuck on speed over anything else, with sights a heavyer arrow should'nt be any problem at all...

Dr. Ashby has some good info on arrow set-up's and the reasons why, each little step is good for bowhunters IMO...

[JACK]

not to shift direction of this thread,but you guys shooting the heavy weights should run your set-up thru a kinetic energy chart. Heavier is not always better. There is a spot between toothpick and lincoln logs that is the best for each individual set-up. Chrono your arrow and use this...http://www.goldtip.com/calculators.aspx

There is also a FOC chart below it.

 

Why didn't I think of that?

 

Ok I did it...and threw the MOMENTUM calculation in just for fun

 

Old set up...385 grains @ 315fps = 84.81 KE and 53.85 MO

Current set up...682 grains @ 250fps = 94.63 KE and 75.70 MO

 

Now what?

[AverageJoe]

hehehe TrphyHntr...

I shoot a BW recurve, 49lbs@ 30inches, GT expedition carbons, feather flechings and full length 30inch arrows and my FOC is at 14% right now (I am at the lower end of overall arrow weight)(want to go higher) with 100gr Muzzy b'heads, alot of stick bow shooters have higher FOC's(check-out the monster 250-300gr. b'heads stick-bow shooters have on the ends of their arrows) then wheelie bows to get better penetration with the lower poundage they shoot, wheelie shooters seem to be stuck on speed over anything else, with sights a heavyer arrow should'nt be any problem at all...

Dr. Ashby has some good info on arrow set-up's and the reasons why, each little step is good for bowhunters IMO...

Just two different ways of thinking. I like to minimize any error and have the arrow get to the animal as quick as possible while hunting that is why I go for speed. I still get plenty of penetration with arrows in the 380-400 range so no need for me to go up to 450 or 500. I also shoot at further ranges while hunting so that is why speed is important to me.