Gun Animations

Began to be interested in modding. An idea to re-release the vanilla pack of weapons with improved animations and models appeared. Faced with the problem of weapon animation in blender. Question for experienced: how to animate the right hand without animating the right hook, it was useful for animating bolt rifles (timberwolf hammer animation) etc. when you need to animate the right hand, but leave the right hook in the same place. I tried to remove the connection of the hook and hand bones, but it broke the animation in Unity, I also tried to simply move the hook to the 3D cursor on keyframes, but it looked bad. So what is the right way to do it?