"My Walmart" carries them but in very limited quantity. Or did carry them when I was last there about 6 months ago. The manager once told me that they "tried not to keep more than a box or two of any given caliber/type on hand". On more than one occasion the clerks staffing the Sporting Goods desk made strange and even rude remarks to me when I purchased ammunition from them. When I asked if I could pay up front with my other purchases, one clerk responded "Sure, just as long as you don't shoot the place up!" Such friendly, good natured banter. I complained to the manager both times but didn't put a lot of effort or emotion into it.
But this is just one of the reasons why I don't do Wally World any more.....