Most of the time, the term unfired also means unused, not handled, etc. But exceptions can happen. I've seen guns with some finish wear (including turn ring on the cylinder) that were, as well as could be verified, "unfired".
But they had been handled, and the action worked, (unloaded) a lot. Its rare, but it does happen.
More common is a gun that has been fired, some, but still looks pristine. Simply put, unless you PERSONALLY have owned the gun since it was first sold, there is no way to tell if it has ever been fired, outside of the factory.
A small amount of shooting leaves no trace that is detectable to anyone outside a lab, if the gun was cleaned carefully. And a lab might not be able to tell either, because the gun was test fired at the factory, once, at least. One story I heard was that once upon a time, one factory shipped their guns without cleaning after test firing. First, it saved them a bit of money (employee time) and second, it was proof the gun had been fired and did work.
Seriously, even with ALL the box, papers, hang tag, etc. there's no way to prove any gun is unfired, other then taking someone's word for it.
A previous owner could have put 6 boxes of shells through your Winchester, cleaned in well, and vacuum sealed in shrink wrap for 30 years. How would you, or anyone know?? By taking the seller word? That's all there is, really.
