If you're living in Oregon they just passed ballot measure 114, which means that you can't have magazines with more than 10rds after a specific date, and also that the cops (Like the notoriously fascist Portland Police Bureau) get to decide who can and cannot own a gun.
But there's a loophole; Get your magazines before 114 goes in to effect and you can keep them, although you are required to prove that you bought them before the day of doom.
So if you might every want to get an AR, or just feel like it, it might be worth it to pick up a bunch of mags now and box them up with the receipt just in case.
A lot of gun people seem confident this will get struck down for various reasons, but you're absolutely right.