For shooting & reloading supplies, I usually find Cabela's pretty tough to beat (although for some reason Midway USA is a lot cheaper for scope rings and bases). And since they don't have a store in Missouri yet, I don't have to pay sales tax. But you're from Illinois; I didn't think you flatlanders could by ammo by mail (I grew up in the Land of Lincoln).
I bought some Black Hills .308 Win in the past and have re-used the brass which has a black hills headstamp on it. Picked up some .223 ammo from them recently and noticed it was military brass.