I've killed 16 deer with mechanicals, my arrows typically carried about 60# KE. I got a pass through 13 out of 16 times. The 3 times I did not get a pass through? Twice I used a 2'' cut mechanical and once I hit spine. If I used a head like the Rocket Miniblaster, Steelhead, or Sidewinder I always blew right through. (I also shot 6 more deer with fixed heads and got pass throughs). I'm not using 2'' mechanicals (Rage); I'll stick with conservative 1 1/2'' - 1 1/4'' heads; 60# KE is sufficient.