VSSA has heard from some members that buying ammunition at Walmart has been difficult of late. Some attributed that to the fact that the administration was trying to put pressure on retailers to enact policies that the administration favors, including limiting access to ammunition. The Washington Times reports that Walmart is restricting purchases to three boxes per customer per day. Walmart says this is because of the increased demand and the inability to keep supplies to meet that demand.
Walmart in the past has cooperated with New York Mayor Michael Bloomberg on firearm sales schemes like installing video cameras to record sales. So, it's no suprised some are skeptical of this new policy. However, in this case, it is probably true that the policy is driven by increased demand. One of the local gun shops in the Richmond area announced a similar policy on their Facebook page and that was driven by the increased demand for certain ammunition of certain calibers.
Update: Colonial Shooting Academy is also limiting ammo purchases to 2 boxes per person for use on the range due to recent market demand.