I recall Norma 150gr factory loads back in the 60's and 70's were around 2800fps MV so yes Norma did load to the CIP specs. Unfortunately they were the exception and even today almost all 7x57 factory loads from various manufacturers, both European and American, are down quite a bit in MV compared to the 7mm-08 loadings.

The Brits underloaded most of their cartridges because they didn't have the powders back then, even when they went from cordite to the nitrocellulose granular powders such as the Nobel range they still tended to underload.

While the 7x57/.275 can definitely be improved and loaded to the same if not higher level than the 7mm-08, the vast majority of shooters are not hand-loaders.