Is Stopping Power a Myth?

Is stopping power a myth? Does a .357 Magnum pack a harder punch than a 9mm? Or is there really no difference in the bullet’s impact?

I don’t know and it seems the experts can’t agree. But we have these swinging steel plate targets that deflect the bullet to the ground when shot. When I shoot the 9mm, the targets swing like they’re supposed to. Not always, but sometimes when I hit the targets with the .357, they practically flip over.

Because it’s only sometimes, I can’t say with certainty that it’s because I was using a .357 Magnum or if it’s because my aim was a little better with some of the shots. But the targets don’t flip like that when I use the 9mm, so maybe it is the .357 that makes them flip.