TFox this thread is pretty interesting since I'm experimenting with ultra heavy arrows myself. I tried to build the arrows based on the recommendations from theAshby reports.In order to achievean FOC of at least 19%, I had to use quite a stiff shaft that could handle all that weight up front. I ended up with 26.5" Axis FMJ 340's with 4" helical feathers, 100grain brass inserts, and 160grain Grizzly BH's with 100gr steel adapters. Total arrow weight 675grains
. It's for my 82nd set at 54# and comes to about 12.5gpp.