I have just picked up my first air rifle, a NP break barrel. Nothing high end first, waiting for a little experience under my belt to get a good idea of what I'll be looking for when I finally drop some $ on a decent rifle. That being said, if I hold my rifle, uncocked & unloaded, across my body barrel in left hand stock in right and I rotate the rifle along it's length axis in my hands, keeping barrel and stock level so scope would move away from me and back towards me, I can hear something moving slightly inside the body of the rifle. Is this normal/correct or is there an issue? Thanks