Well Saltydog - I realize that the hog analogy was a bad one. As far as tests in ordinace gelatin not being meaningful... as you an hogdogs have pointed out - it's not meaningful for a should shot on a hog. The shot hits the sheild or hits bone and stops - and that doesn't matter if it is birdshot or buckshot up to #00. Those loads are all going to pretty much perform the same in a hog shoulder shot scenario - they are going to stop at the gristle or bone.
I wish I hadn't used the hog analogy becasue the OP was for HD. The idea behind ordinance gelatin is that there is a correlation between how projectiles behave or perform in gelatin and how they will generally behave when hitting a human body.
Yes, sometimes a pellet or number of pellets might hit bone, or a belt buckle, or an object that a perpetrator is carrying (lots of variables) and the shot will not perform the same way it did in gelatin. But generally ordinance gelatin is a good predictor.