The 300 Savage was the parent case - for the .308 Winchester.
The .308 Winchester was designed as a machine gun cartridge.
The reason why the .300 Savage was not loaded with a high pressure load was because the factory could not ensure that the older model 300 Savage rifles could handle the higher chamber pressures.
Because the Model 721 / 722 came out in the 1950's, you can bet that the rifle is as strong as a ox and can handle the added pressure with no issues. I would see no reason to ruin a excellent rifle chambered in 300 Savage to change it into a 308 Winchester.
It would be like putting a mustache on the Mona Lisa.