In OR, I have never seen a "no guns" sign on a Walmart. If the sign is not there, concealed carry is legal by state law.
I have not seen OC inside a Walmart in OR. Don't know if they have a policy against it of if I just haven't seen it.
Lately I have seen a few people open carrying revolvers with 8" to 12" barrels. I don't know what's up with that, but they are doing it.
12” barrel is one heck of a statement.