Pondoro Taylor in African Rifles and Cartridges writes that .350 Magnum Rigby was introduced to chase the .375HH - 'owing to the incessant demand for higher velocity and flatter trajectory'. He spoke very highly of this cartridge with a 225 grain bullet - 'at ranges up to at least 150 yards kills just as instantaneously as the .375 Magnum'.

.350 Rigby, the 400/350, threw a 310 grain bullet. Taylor loved it - '(I) can truthfully state that I have never owned a more generally satisfactory medium bore.' He goes on to agree with the statement 'I found that the .350, besides being unrivalled for smaller game would do all that the .450 would do with the bigger.' Excepting very dense bush and the inexperienced man.