Smith-Corona and Remington had WW2 contracts for the 03/A3 rifles, which were nothing more than a slightly altered M1903 Springfield Rifle to enable them to speed up and reduce the cost of production. In all cases, they were chambered for the U.S. government issue round at that time of .30-06. I have had several Smith-Corona's over the years, but the only one I have at this time is an unissued, unfired one, still in cosmoline.
Don