"The Box O' Truth - What you always wanted to know... But were unable to test yourself!" -- Old Painless
Many thanks and two tips of the old boonie hat to John54 for forwarding me this link:
The Box O' Truth website is run by Old Painless, a Life and Patron Member of the NRA who holds certification as a Pistol Instructor, Rifle Instructor, Shotgun Instructor, Personal Firearms Defense Instructor, and Home Firearms Safety Instructor.
In Old Painless' words:
The purpose of the Box O' Truth is to test the penetration of various rounds. There is only one way to know how much a certain round penetrates. You must shoot it into a medium and see for a fact.
Go to his site and observe all the tests. Great stuff. And be sure and subscribe to his newsletter.