extreme FOC

[SCS]

I was glancing through Dr. Ashby's reports on extreme FOC. How many of you use this thinking in their arrow building? What do you consider extreme FOC? Would a 28" 35-55 GT arrow with 50gr. inserts and 145gr tips be considered x-foc?
Steve

[kadbow]

I use a 100 gr insert with 145 gr points on my GTs and they fly great and the total arrow weight is over 500 gr.  I do this on both 35-55s and 55-75s.

[SCS]

What fletchings are you using? Can you get away with smaller fletching with 245gr. on the nose?
Steve

[Orion]

High, but probably not extreme FOC.  I believe Ashby defines high FOC as 15%-19% FOC, and extreme as 20% or more FOC.  Figure out your FOC with this formula.  Total shaft length (from nock throat to back of point) divided by the distance from the nock point to the balance point of the arrow, minus .5 x 100 equals FOC

[fyrfyter43]

I would consider extreme FoC anything over about 20%.

To give you an idea where you're headed, I'm shooting full-length GT3555s (30") with 4-4" low-profile nanners and a total of 300 grains up front (50 grain insert and 250 grain head). That comes out to 24.7% FoC.

[J-dog]

Go to the How to forum, Rob has a Xcell calculator onb there that is the ticket. Just need to plug in your info and it will spit out the FOC.

J

Course you can get the formula yourself but??

[JRY309]

most of my carbons are running 16-19%,I like to tune my arrows and that is what they come out at.I think you can tune for extreme FOC easier on bows cut past center,but on longbows not cut to center that is more difficult.On some of my longbows not cut to center I've gone back to aluminum,they just seem to being alittle more forgiving and easier to reach a heavier weight.

[Apex Predator]

I shoot CE Heritage 90s with 86 grain inserts and 250 grain heads.  They qualify as extreme, and would probably shoot through my car!  This is out of my 53@27 Hill.

[beyondmyken]

using 5 1/2 in 3 fletch, I can shoot 190 gr Grizzlies + 125 gr steel BHA + 100 gr brass inserts with a 35-75 goldtip from 3 different bows:  Fedora xtreme 54 lbs, Fedora recurve 60 lbs, Trident 58 lbs.  I can use 145 gr broadhead on the same bows with 4 4 in fletches but not the 190 gr.

[elkbreath]

I shoot 26% off of a homebuilt longbow.  Arrows tuned bareshaft awesome.  yet to get this setup in an animal.  8 more weeks!

[Doc Nock]

SCS,

I had to go back and review some PM's with Doc Ashby before I shared this...

In emails, I'd asked "what's EFOC and where does it start?"

His reply was that in the testing he and his associates had been doing, they were all in the 25%-28% FOC range... and that 2 1/2" 3 fletch were stabilizing the 190 Griz El Grande ok with even mildly smooth release.  He didn't know how low on FOC one could go and still have the effect they'd noted with EFOC...so it had to be on me to experiment.

A guy in New York, Drew Reniff, made me a A&A Feather chopper by altering a Raptor Chopper. He is getting away with 2" feathers, big broadheads and is only shooting 18% FOC arrows.

I chickened out and had  him make my chopper for 3", but with some work, it'll go to 2" A&A profile...

I've been messing with the 3 fletch 3"x 7/16" high fletch. I've not tested the 3" with broadheads yet, but they are noticably faster with field points and drift less in a cross wind... I have 22.3% FOC on my GT set up.

FWIW...  

[hunt it]

I am using 29 1/2" GT 5575 and 3 - 5" shields with 300gr up front. They fly like darts and hit hard, out of 64# Shawnee/Dakota - non carbon. Bob Morrison nows has 300gr ss field points if anyone is looking for some.

[SCS]

Thanks for all of the replys. I have some 35-55 GT's for my compound that I want to experiment with. If all else fails, I'll just cut them to work out of the cp.
Steve