Well, I just finished up tuning two batches of carbon arrows and was wondering about my foc. Though I did not set out to achieve EFOC this is what I got with my 49@28 60" Kanati:
GT 35/55
29 BOP
3 Fletched w/5" LW Shields
225gr up front
505gr total weight
18.8% FOC
CX 150
29.5 BOP
3 Fletched w/5" LW Shields
225gr up front
552gr total weight
17.7% FOC
Again, I did not set out to achieve EFOC but this is what is working out of this bow. Anyone else get similar results with carbons? And if so (or if not) what are your thoughts on having such a high FOC?
Your not that far over standard FOC. High standards FOC is 15%. Your below EFOC by a bit as well. Your FOC should work great and those arrows should kill a lot of critters.
I'm no expert, but I consider 17% and 18% FOC standard. If you were talking 30%, then I'd say you were a bit extreme. None of it matters much as long as your arrows are flying where you want,...and flying straight.
Your set-up seems quite reasonable.
To desire, considerably more FOC then one needs to grasp their objectives.
I'm at 20.6% FOC with my 51#@28" longbow using a Heritage Carbon express 250. It seems to be perfect for this bow, I love it. Same arrow for my 56#@28" longbow 17.2% FOC. Again perfect for that bow. Total arrow weight 620gr., and 570gr. respectively. I wouldn't consider yours extreme foc, but no worries if they fly true.
Unless you shoot a very light head on carbons, you will always end up with higher than standard (7-10%) FOC because the arrow shaft itself is so light. I believe Ashby defines high FOC as 15-19%. Above that, extreme FOC.