Where I hunt, both in NY and PA, they are legally " unloaded" when you remove the cap from the nipple, or the powder from the pan of a flinter. You can then leave them loaded with bullet and powder, which I do, but I leave the gun in a case outside in a shed or vehicle until the hunting is over. Have left one loaded for up to a week, and it still fired O.K.

I see no reason why you could not legally fire the thing into a safe backstop after dark, if you wanted to unload it. As long as you weren' t firing at game after legal hunting hours... Ask your local friendly Conservation Officer!!