That’s actually a great way to show someone that they are flinching. I’ve done similar.Kind of did the opposite to a friend. when I was a ffl I ordered him a S&W 44 mag. He couldn't hit anything with it. I told him he was flinching, he said no way. he laid the loaded revolver on the bench to take a leak. I pulled a random round. he came back in recoil on the empty chamber almost as much as when he fired a round.