What is considered EFOC.
According to Dr Ashby, 12% and under is considered moderate FOC, 13% to 19% is heavy FOC and 20% or more is EFOC (extreme). Both of my bows are shooting heavy FOC arrows since they're slightly above 17%.
Dr. Ashby Reports (http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=forum;f=24)
And in your spare time, this will tell you everything you could ever want to know about EFOC!
:)
Don't forget Ultra-EFOC at 30+%