Hi,
I put my weapon (pistol) as a main camera child
-> Camera
----> Weapons (group)
------>Pistol
I tried to put a group between the weapons and the pistol.
But i have some odd effect when i move the player camera, the weapon seems to rotate a little too.
Here some images to show the effect


So here you can see that when i move the camera up and down i show a little more of the camera