 The larger action was originally meant for Rigby's interim .400/.350 round, but in 1911 the company introduced the .416 Rigby cartridge for rifles built on the Magnum Mauser action.This was the first magazine rifle that could perform on a par with the powerful Nitro-Express double rifles, for one-third to one-fifth of their prices.John Rigby was well versed in Nitro Express cartridges as well.