I don't think the effect will be the same (as Dicks).
Dicks is a sporting good store. Walmart is a huge department store that sells everything (and some ammo on the side).
The majority of Dicks customers are sportsmen (some of whom care about this). Walmart is everyone else (who won't give a $hit about this).
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But, it sucks, because I have bought ammo at walmart for many years on a regular basis.