I would also be extremely concerned about losing a hand or fingers.

I have read the major problem reloading steel case (not a re loader yet but I still have read up on it and am learning as much as possible) is the fact its not as elastic as brass.

This causes the case to suffer more stress weakening it when its fired. Then more stress is added when the round is re sized and reloaded. I would think that the unsupported chamber on many 40 S&W caliber handguns would also exasperate this issue.

Then we add in the fact the 40cal S&W is a extremely high pressure round. This to me looks like we have a almost perfect storm for catastrophic failure.