While an excessive BC gap is not ideal, it could not cause the amount of leading I was getting by itself. In my gun the cylinder was sitting slightly above alignment with the bore. This caused part of the bullet to be shaved off every time the gun was fired. The splatter collected just above the forcing cone, and some hit my forearms and face.

This was not acceptable by any means and the gun had to go back to S&W. I have read past threads about similar problems with 317s, but reports are that the guns come back completely fixed.