Starman,

I don't use ballistic gelatin or wet paper, because I have found through plenty of experimentation that neither resembles shooting animals.

You might read the chapter in my most recent book on pre-testing big game bullets to find out what I do use, because the "test media" used more closely replicates the results from shooting lots of animals.

“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck