ORIGINAL: aeroslinger

fastfire, I don't doubt the mechanicals need more KE but on the spitfires, as well as others, the blades are flared out at the ends and they also don't have the rubber bands and it seems as though on entry the blades would be forced open by contact as it pushed through. I don't know the science behind it enough to say one way or the other, but it just seems like it. I take my spitfires and take them apart and put them back together to make sure they open easily. I can push the blades open without much effort. It sure doesn't seem like it would take 1/3 of the energy just to open the blade. Like I posted before, I had a passthrough double lung and sliced a rib clean in two on exit like a surgeon's blade and the arrow buried in the ground from about 15 to 18 yards. I guess I'm just packing a ton of energy.
Forgot to mention I am using a much heavier arrow than gru. I'm shooting 29 1/2" 2315 xx78's with 100 g spitfires from a Pearson Anaconda.