Thanks much also Stan. I doubt all would accept it as fact, but still you've shown us one place to look. Did he mention what caused that lower third of the shot column to show more distortion? I suppose if we assume they're all distorted the same, and crack open the ole text book, then some equal but opposite force acted on the top third. But, except for the blowup pictures, there doesn't seem to be much holding the shot in barrel when a shell is lit off.