IMO the single bevel are aweful. They have brazing in the way of sharpening and it takes a lot to get through that back to metal that can be sharpened. I would stick to the double bevel. I shot a deer in the head with a delta and the broadhead went all the way inside the brain and stopped on the bottom front of the skull without a glitch. The deer did a back flip and broke off the arrow and the broadhead was left inside the skull. In hindsight, I should have kept the skull.. Zwickey heads are built well.