RE: How much KE is enough?
There are deer and then there are deer. A big old rutted up buck from the north is a beast you need some and some more to put him down and find. He ain't yours until you find him. In other words, know your game.A deflection off a rib bone sending the shaft south can happen making him hard to find. Bigger deer, bigger bones.
I used the 340 beman ics hunter *elites* this year with a 100 thunderhead and 3, 4" savage duravanes. They worked well although I lost 2, arrows that is, one on one of them bucks from the north. You can get the shafts for under 80. The savage vanes were a big improvement over the standard vane. I was thankful for the holes the thunderheads made.