Doesn't really matter what the lengths are - lay the rod on the outside of the barrel with the tip at the end of the barrel, mark rod at the end of the muzzle, then stick it down the bore. If it doesn't come very close to the same mark, something is up.
Since you're within a half inch of the quoted barrel length, I'd assume it's unloaded, but I'd also want to confirm it. Pretty easy to shine a light down it, or even pull the barrel and pull the breech plug to confirm it.