I do think, though, that in the recent craze of loading vintage cartridges to their max, the 450 3-1/4” Rigby cartridge would surpass the 45-120 simply based on capacity.
The 45-120 can be loaded to 450NE levels, but the 450NE can also be loaded hotter than original as well.
It’s the same thing as loading the 404 Jeffery to Weatherby levels in modern rifles - who needs that?!