i think you're seeing more ammo on shelves because of the limit per person.
Hammond was gold this am for ARs. got three boxes of 100 count .223, they still had plenty of AE 5.56 on the shelves. Academy still has a lot of 5.56 and they have .223, so you can double up on that, and they had bulk 9mm that sold out quickly.
Combining the ammo and upper, charging handle, and muzzle device I bought today, I am done for the time being. Saving the rest for a Tavor and a .300 AAC BLK, and maybe some online bulk deals.