Although there is certainly something to this high FOC principle, particularly when engaging large critters where penetration is critical; practical experience has indicated that the lower FOC arrows using 75 grain heads work pretty well - expecially for lighter game like deer and antelope. Ideally, of course, he should have been advised to get the 340 series arrow. And then he could use 100 or 125 grain heads - or even heavier if desired. But now that the 400 series are already purchased, they are still workable arrows by either lowering the draw weight a little or going to a lighter head.

One of my hunting companions uses the 75 gr. Rocket Wolverine - shoot like field points - gets 2" groups at 50 yards - blew one clear through a 750 lb. bull elk in September. He thinks this whole FOC thing is some kind dated principal - like applying the old blackpowder rule that you need at least a 45 caliber for big game to modern centerfire rifles.