I did a lot of ballistic testing before I selected a bullet to hunt with.
I will just say that if you do the testing, you will learn a lot you never knew before.
Bundled, soaked newspaper works very well for this.
Why is it important? Some bullets will come apart and IMO should not be used for big game hunting, some will mushroom off to the side and will plane wildly in the test medium, heavier bullets in the same caliber will only penetrate more deeply if the are of stronger construction. Penetration depth will depend on the energy of the bullet, and how fast it does or does not open. Smaller bore guns of the same power will penetrate deeper than larger bore. A 270 Win, 30-06 and 348 Win all have about the same muzzle energy. Contrary to popular belief, the 270 will penetrate the deepest, and the 348 the least. That said, the 348 makes a much larger would and will kill much faster.
Bullets that develop mushroom petals (instead of a full mushroom) will penetrate far deeper than full mushroom bullets.
This information helps you to select bullets that consistently produce clean kills and is (IMO) very important.