VHE- sounds like something is loose in action - normal?

[jsd245]

So I have a new to me VHE. Gun is in really good what looks like original shape. Everything functions as it should, ejectors eject, gun fires, safety resets and works properly. Locks up tight with no looseness, lever is to the right of center. Hoewever- if I hold the gun and dip and raise the butt I hear what sounds like a small piece of metal sliding back and forth in the action. It does this if the gun is cocked, not cocked, or broken open. Its not as of there is a loose piece just rattling around in there- it something obviously in a fixed position sliding back and forth. Is this a problem? If it is what could it be? I have not tackled pulling the stock off and cleaning and lubing the action. I guess I should.