Problem with animation in blender

hello everybody
i have really weird problem with keyframes in blender
i have ak47 model and 2 hands…c7d0d07b1_scaled.jpg
when i want to key fram this thing(i dont know its name) the other objects will change their position !
the body is parented to the left hand and the right hand is parented to the body
i want to animate shooting but i cant animate because of this

no one can answer this question?
i think this a bug in blender 2.80+