HANKFAN:

You can allay your concern by making a pledge that you will never intentionally shoot your mechanicals into hard and dry plywood, steel drums, hard rubber vehicle tires, and any other median that the broadhead is not operationally meant to penetrate.

Also, call the broadhead manufacturer and advise them of your concern regarding certain and apparent defects that resulted from shooting plywood, steel drums, rubber tires, etc. I would be curious as to what would be said to you.