I have used the wet phone books for about 30 years to get an idea of what to expect from a bullet in terms of terminal performance. You bundle them with twine in stacks about 10" thick, and soak them in water for 24 hours. They swell as they soak up and it usually takes two stacks to stop an expanding bullet. The general "benchmark" for this type of testing is a common round, like the 30/06 Remington 180 gr. Core Loct. This bullet usually will penetrate about 12" in the wet phone books and make a certain shape "wound channel". You can then compare other bullets and , knowing from field experience what the 180 Remington Core Loct will/won't do, make projections about other bullets. Not a substitute for actual field testing, for sure; but a good indicator of what to expect.