https://youtu.be/T26cV_M_oAE
I've had several people tell me that at "close range" birdshot is fine for defense because it all hits in a single mass and acts like a slug. That's obviously stupid but hey, why not? Let's see what happens. I place the barrel of my shotgun a few inches from the gel block to see if it's possible for birdshot pellets to penetrate adequately when they impact together.
Also, because I can't get enough of that TSC: