Carrying an AR pistol in a backpack?

I’m in the process of building an AR pistol that I’m going to keep in a backpack. I realize there are varying laws about this depending on state but I’ve had trouble finding solid answers on whether or not I can carry my backpack+gun in the state of South Carolina this way. I don’t think I’d want to carry it down the street or anything, but maybe to go hiking with. Does anyone know the legality of a concealed carry “pistol” AR in a backpack? via /r/CCW http://ift.tt/2Did90g