Note that the tests were all some sort of buckshot or slug. I switched from #4 birdshot to 00 buckshot in my shotguns based on the following from the “Box of Truth” website. Not scientific, but makes sense to me:
http://www.theboxotruth.com/docs/bot14_4.htm
2. Remington 55 grain JSP and Frangible 5.56 also penetrated all 4 walls. So did the .30 Carbine.
When shooting rifles, walls are concealment, not cover.
3. 00 Buck penetrates 4 walls with ease. It is a great “Stopping” round, but there is a price to pay.
Until someone invents a “Phaser” like on Star Trek, anything that will stop a bad guy, will also penetrate several walls.
4. Birdshot does not excessively penetrate drywall walls. But it does not penetrate deeply enough to reach a bad guy’s vital organs. Birdshot makes a nasty but shallow wound. It is not a good Stopper.
Use Birdshot for little birds. Use 00 Buckshot for bad guys.
Thanks; good advice. Guess I’ll stay w/ .00 buck loads. I don’t shoot little birds.