Check out Kreisler Outdoor Center in Clinton, Missouri, on the east side of the little mall with the Walmart at the intersection of Hiway 13 and Hiway 7. Small shop with both hunting and fishing gear as well as reloading supplies. It's about an hour and a half from you.
417 Guns in Springfield no longer carries reloading supplies.
In Springfield, besides Bass Pro, check out Cherokee Firearms at 1544 North National Ave. A full service gun store with gunsmithing, reloading supplies, and one of the country's best gun engravers, Jim Downing, on site.
In Bolivar, find J. D. Shooter's Supply on the west side of the town square, across the street from the courthouse. Guns, gunsmithing, some supplies.