Long time listener, first time caller........
I have had amazing luck with the Wal-Mart App combined with being friendly to the department manager to determine when they are stocking the shelves, we have several stores within 15mins of my house. You would be surprised what kind of information a smile, and some kindness will earn you. I can tell you Wal-Marts sporting goods employees are dealing with some real DB's on a daily basis, they are tired of this ammo shortage too.
I buy virtually anything I can find, because I have several employees, and friends that are either to lazy to look for ammo very hard, or cannot afford the gas to drive all over town on a hunch they might find what they want. So we have a cooperative now, we all buy anything we can find on the list of rare items (22LR, 9MM, .223/5.56, .40, .380) and we trade with each other in an effort to thwart the flippers from taking advantage of the free market. So far, over the last several weeks, we pretty much have all we want for stocking up. Its still tough to go to the range and shoot with the fear of not being able to replace what we have. Though it seems to be loosening up a bit lately.
Good hunting.....