Brother, usually checkers kills cc's.
And you are still new to the online carding scene and want to card walmart or home depot.
This is commit-suicide.
At 1st get used to the scene by carding some easy stores, you can begin with Fandango then one by one you will be used to the scene.
Read a lot and ask questions's, you are in your home, and I will help you if I can.
Check the cc by yourself, don't use checkers, use it only when you are pretty sure the cc is declined.
To be honest, there are some checkers which I hear that they are good, like electronicpromo.net
Walmart needs old account to be carded, like amazon, eBay, .......... etc.
And try to use fulls, the amex fulls of Gangster is excellent, you will see how much there in the cc, maybe the cc used doesn't have $1.
Wish you the best of luck