All guns are proof fired with a higher that standard pressure proof load at the factory before they are boxed and shipped. This is to make sure that there are no unseen problems that would result in the gun blowing up the first time you shoot it. Proofing is standard practice for all smokeless arms in the U.S. and Europe. Some manufacturers even shoot a group with each rifle to test the accuracy and send the target with the rifle. If you use the standard that a fired gun is a used gun, then all smokeless cartridge arms are used before they ever hit their shipping box. Muzzleloaders, on the other hand, go to the consumer unfired. The only exception being the Savage 10ML-II, but it is the exception as Savage Arms voluntarily chooses to proof fire them but is under no specific obligation to do so.
Mike