RE: FOC and arrows
I like to keep my Broadheads between 12% and 15% FOC. It sounds like you are good to go unless you decide to experiment with Extreme FOC. I built some FMJ's late last year using Brass HIT inserts and the FOC ended up over 20% They fly Awesome and group unbelieveable at longer distances. Those 500 grain arrows leave my Guardian with next to Zero noise!
Dan