It is evidently a gyroscopic effect, being reversed in direction by a change from a right to a left-handed twist of rifling, and being increased by an increase of rotation of the shot.
This gives (in essentials) the theory of the gyroscopic pendulum.
The name for both these twisting motions is gyroscopic precession.
It's so advanced, other companies have purchased patent rights to use the gyroscopic technology in other devices like the makers of the Life Pen.
The input device may look like a TV remote at first, but delve a little further and you will find gyroscopic technology within.