Bones stick to other object?

I have an arm, and I have a gun. I want to make it so that I can move the gun around and the hand “sticks” to the gun, but the gun is parented to the hand…How is that done?

rAther than parenting the gun to the hand, use a child of constraint. and make the gun a child of the hand bone in your armature, that way the gun will stick to the hand but by reducing the influence in the constraint the hand can put the gun down, either on a surface or in a holster whatever. you can use multiple child of constraints on a single object so the gun could also be a child of the holster and wil still stick to the character as he moves around