If you are concerned about penetration, and want a good read, look up the Dr. Ashby reports. He goes heavy and a 2 blade single bevel. Uses the analogy of getting hit by a fast ping pong ball vs a slow moving bowling ball. His info. basically comes down to making a structurally sound arrow setup, with a trajectory you can live with. His theory is to prepare for the worst. most of our setups should blow thru for a double lunger, but how often do you try a heart shot, or the deer moves and you get a shoulder,ect..... If you follow his setups, you should still blow thru anything presented. When I started experimenting with different tip weights, my bow, which I thought was quiet, became totally quiet, all you heard was the arrow hitting the target. There are pros/cons, but for me it was all cons except some speed loss. Now to just find a deer that will co-operate.
Its all up to you and what you want to experiment with.
