Interesting test. Is animal tissue and a spruce log similar in consistency?
One would suspect that since spruce is denser than soft tissue, it would cause a bullet to open up more/faster. The really interesting thing for me were the pictures posted by Klikitarik. The bullets came out of animals and they looked very similar to my picture - except his bullets opened up even less. Seems to make sense to me.
Why not test them on rocks? Rocks are denser than tissue.
What I'm saying is that unless you are testing with a similar medium, all you've really proven is that you can shoot through a bigger tree with a Barnes than you can with a Partition.
