Of course the Lott came AFTER the win mag.
And Jack Lott said in print numerous times that all he wanted was a cartridge that consistently gave 2150 fps with a 500 gr bullet. With modern powders the 458 Win easily beats that and Hornady ballisticians assure me that AT EQUAL PRESSURES, there is only around 60-80 fps difference between the 458 Win and the 458 Lott.