A great video on a problem that a lot of new shooters have. We saw this a lot on the firing range at the police academy. Once the proper grip and proper sight alignment were established the only thing that applied pressure was the finger to "press" the trigger to the rear until it fires. We would coach them to push with the strong hand, pull back with the weak hand, front sight, "press". A real give away that they were applying pressure with their whole hand is when their groups went towards the weak hand.