It's not going to help. Never go into Walmart. Ever. Online is tolerable but the "People of Walmart" is more of the standard than the exception. My sister worked different levels of security for target over the years before becoming a corrections officer. She liked it a lot.
Hope you have extra magazines. Some of those heftier shoppers can take quite a few shots to drop, especially when they're hopped-up on bargain hunter's adrenaline.
We stopped by a walmart on our way home from dinner. We didn't go in, but the parking lot for the mini mall that held the walmart was full! Wmart was the only store open! Eff that! I would have surely murdered at least one shopper.
