My 2 cents, Go with a cut on contact broadheads. I've used both and if you make a perfect hit and don't hit bones then the expandable will do a great job. Yet when passing through the rib cage that's hard to do at times.COC's will go through easier and I believe they will glance off ribs and keep on going through. A clear pass through is what you need for the quickest kill and best blood trail.