I agree with Huvius that it is most unlikely

The 450/400 3" was made with a thick rim and slight shoulder difference so it (as a powerful Nitro cartridge) would not chamber in older 450/400 3 1/4" rifles made for Black Powder only

The .333 Jeffery was a .404 Jeffery shortened and necked down

According to Hoyem the .333 flanged was "a rimmed version of the previous (.333 Jeffery) cartridge, made by several ammunition makers

The extra rim thickness IMHO preclude it from being based on (another maker's?) case and probably not the 450/400

TH