Unity and gun rotation

I make the 3-rd view mode (like game Foreign Legion) and “put in hands” my hero a gun. How I must make that gun rotate like camera (in camera transform there are many problemms(rotate only x-quaternion)). I mean: camera “watch” up - gun (hand) rotate up. Camera - down and hand - down. Please, help me!!!
Sorry as my grammatic - I from Ukraine and know English not very-well:)

simple way - attach gun to camera.

more hard way - take rotation using script from camera and apply it to gun