How to find my arrows FOC??

Bullet Hole Bailey · 02-12-2008, 07:49 AM

Well I was reading something on this and it said that it shouldnt be as low as 8% but not as high as 15%. I have no idea how to check this and I was wandering if any of you guys could help or gve instructions?

Thanks!

GregH · 02-12-2008, 07:58 AM

Remove the point from your arrow, measure the length of the arrow from the bottom of the nock groove to the tip of the point insert and divide by 2. mark that as the center of your arrow.

Install the point, balance it precisely and mark that spot. It will be forward of your center mark.

Measure the distance between your center point and the balance point.

That distance divided by the arrow length equals the FOC as a percentage.

Example: 30 inch arrow with a 3 inch center to balance point equals a 10% FOC.

I have shot arrows with a 12% FOC that worked great.

GMMAT · 02-12-2008, 08:02 AM

What happens when your arrow gets really FOC "heavy"?

No idea.

bawanajim · 02-12-2008, 08:04 AM

Hell I just though he forgot where he put his arrows.

MOTOWNHONKEY · 02-12-2008, 08:07 AM

Quote:

ORIGINAL: GMMAT

What happens when your arrow gets really FOC "heavy"?

No idea.

Instead of the front being along for the ride it trys to help steer the arrow. If that makes any since.

GMMAT · 02-12-2008, 08:10 AM

I've never heard it put that way, Chris....but it does make sense. Would you need to make SURE you had enough ass in your spine? (Does that make sense?)

Also....is this an advantage or disadvantage to a target shooter? Any shooter?

Thanks!

GregH · 02-12-2008, 08:19 AM

When shooting indoor NFAA 300 rounds, I used 2613s with a 220 gr point. Can't remember what the FOC was but the arrow went where the point said it should go.[8D]

MOTOWNHONKEY · 02-12-2008, 08:21 AM

I can't answer your targetshooting tech questions because I just dabble in that for fun only. As far as spine I think you need the proper flex in the shaft. Overspined I guess is better then under but there is the perfect balance. The perfect balance shaft to me ex sorbes (sp?)the bows energy while the over spined shaft gives it back. I seen a cool video of slow motion over and under sipined arrows that was a real eye opener. I'm going to try and find it. I seen it several years ago.

PA Hardwoods · 02-12-2008, 08:35 AM

I am a huge proponent of High FOC arrows. My setup last year was a 2005 Old Glory set up shooting 65lbs with 453 grn arrows with a FOC of 22% (205 grains up front on the arrow) shooting at 260FPS with Kinetic energy of 67 ft lbs. My bow has never shot better than it does with a high FOC setup. those arrows are flying great. I highly reccomend tinkering sometime with an arrow setup with a FOC over 18 or 19 trust me you will notice a difference. Yes it will slow your arrows down and you may have to go up in spine weight but, trust me arrows with that weight up front really pack a punch. Read some of the reports by Dr. Ashby on broadheads and you will she he is also a huge propent of this also.