Walmart has been beat to death....but here you go.
Policy is to follow the law of the state the store located.
(1-800-925-6278) Questions regarding a Wal-Mart Store issue
702 SW 8th Street
Wal-Mart Stores, Inc.
Bentonville, Arkansas 72716-8611
Email contact link: http://walmartstores.com/contactus/feedback.aspx
Audio of Walmart Policy: Walmart_Firearm_Policy_Call.mp3