There are 'two schools' on bullet penetration. I think you will find the forum divided on this point. Some folks like plenty of expansion, others swear by hardcast bullets that will expand less and exit the animal, one of the therories being 'two wounds' the exit wound being the larger of the two and making a better blood trail, but........Better expansion, will retain all of the force of the bullet in the animal (more knockdown, less tracking).......then there is the 'third' school. The Barnes 'X' and Black Talon.....The Talon cuts a path instead of smashing a path and closing blood vessels, the Barnes 'X' does a combination of both, even though it mushrooms, it is a more raggy mushroom with sharper edges, and I have heard people say it makes a devistating wound channel...or tunnel. But then...they are 'touchy' bullets for accuracy.
Anyway..back to your question...Penetration tests are not going to be the same as on a real animal. Just hitting a rib can make a big difference as opposed to hitting between the ribs and lung matter, there wont be much to stop the bullet. A lot of the bullet tests are based on penetration on Meat, and that isnt what I would be aiming for.
Myself, I like a good quality soft point, and load it as hot as possible to still be accurate. I did a lot of research for light loads and bullet performance, and checked out the 'bloodshot theory'. (bullets less than 2500 fps cause less bloodshot and meat damage) I have tried a lot of these loads for ballistics and such, but when it came right down to an important hunt, and meat on the table...I have never any of these loads. I have always used the most powerful load that I had with me and banked more on accuracy and not hitting any of my good meat(in a perfect world) .... It dosent always work out that way.
