IIRC it last a little over a year before stores like walmart and academy took their limits off. This may be longer because the government is buying a ton of ammo. I think they are doing it to keep it out of our hands. You cant shoot what you cant buy.
I wouldn't succumb to panic buying anymore. With some careful looking, I've found all my ammo needs met at normal prices the last few weeks. Maybe all these panic buyers went broke on Valentine's Day trying to appease their pissed off significant others for running up the credit cards.