How do you know for sure? There is a range in town that sells once-fired brass. That range REQUIRES that you purchase the ammo you shoot from them. They don’t always stock the exact same ammo. Sometimes it’s Federal, sometimes it’s Blazer…just depends (probably on what they can find at the lowest price, but rest assured, they charge the same no matter what!). So, since they do not allow you to shoot your own ammo and require that you purchase and shoot theirs, you’d think that, FOR SURE, if you bought their “once-fired” brass, that it would indeed be once fired. But, there’s no way to know what was actually FIRED on the firing line. After buying a box of ammo from the range, anybody could easily shoot some of their own ammo that was sneaked in. There’s no way the range officers can observe every shooter closely enough to ensure they are only shooting range ammo.