Okay, you have a control explosion going off mere inches from your face. It's loud, there's recoil and you want to get your sights back on target as quickly as possible. These are all true statements; you still can't induce any movement into your rifle while the shot is taking place.
Bucking - throwing your shoulder into the shot
Flinching - jerking your body just before the shot
Anticipating - tensing up before the shot