Can someone please help me. The delima i am having is this. Last season I shot Easton Axis arrows, 30" 300 spine, with G5 Montects. This year I am trying Easton Axis arrows, 29" 340 Spine, with NAP Killzone. With my 300 spine arrows, i had clean pass through shots on every animal i shot. This year I have shot 2 deer, and havent got a single pass through. is this because of the Broadhead difference, or arrow spine difference. Both types of broadheads are 100 grains. All shots that are being considered were free of striking any bone, with the exception of ribs. distances are similar as well. I understand that the 300 spine will proly penitrate better, but at 30" DL and 70# in side of 40 yds you would think i would still pass though. any thoughts would be helpful thanx.