From another website:
Our Assessment: In 1924, the Sequoia Import Company of San Francisco imported 1000 Mannlicher Schoenauer bolt action rifles from Steyr. The Mannlicher Schoenauer rifles were very popular in Europe, and made in European calibers. Sequoia convinced Steyr to make the rifles in .30-06 Springfield so that they would be more readily accepted here in the United States. Many of Steyr’s previous models were made in one caliber only, and there was no reason to mark the caliber, since the model defined it. This is the case with the Model 1924 model, and the caliber was not marked on the rifle. Unfortunately, the European look of the rifle wasn’t that popular, or else the prospective buyers thought the rifle too light for the caliber. In any event, the rifles didn’t sell all that well and many were sent back to Steyr to be re-barreled to different calibers, at which time the calibers were marked on the receiver’s chamber ring. Going forward, new rifles made to the same design were renamed as the Model 1925 and offered in European calibers as well as .30-06, with the calibers marked on the chamber ring.