I remember there used to be a limit on how much you could have in your house. I know there was a 5LB limit on Black powder and I don't remember the smokeless number offhand.
In stores there was a limit too, but never enforced. I think the industry sued under "Restraint of trade" because there were more models of powder than the limit. So they argued it was unfair they couldn't display all the different types. So maybe the limitations got wiped across the board.