Our Forum member "flyandscuba" posted this photograph of the results of some newspaper wetpack testing which he and "oldgrandpa" conducted back in the summer of 2006. I saved it for reference in my "Ammunition" folder.
(http://i2.photobucket.com/albums/y30/RichardS/RohrbaughR9S-SeecampLWS380Shoot-out.jpg)
On the general subject of bullet tumbling or key holing, and although it has no particular relevance to the subject of performance of various defensive loads out of our little R9 "pocket rockets," it is interesting to note that many contemporary Russian-made 7.62x39 cartridges contain a modified M67 bullet specifically designed to enhance tumbling.
(If you contemplate this stuff long enough, you get a headache.) :-/