Stopped into our local WM in Detroit Lakes and they had a nice stock of .22, .380, .40, .45 and 9mm. No limitations on amount.
Today I am in Lincoln, NE, and stopped into a Wal-Mart and they were flooded with ammo. Not an issue with any common pistol caliber. Turns out it was a manager on duty and he says ammo has been no problem for that store for a good 2 months. Also, the Fargo store...3 weeks ago...was very well stocked.
Pricier though...$23.96/100 9MM. $18 for the 550 Federal .22's.