I see threads all the time in which someone states that he bought an "unfired twenty-something year old model such and such". It seems bizarre to me that a gun that's a few years old and not a collector's item could really be unfired. Does the term simply mean in sufficiently good condition that it looks as though it was unfired? Or does it literally mean not fired since it left the factory? And if it's the latter, how does one determine if it's truly unfired?