JJDonnelly lists the case capacity of the .404 Jeffery (.520" shoulder) Rimless as being 115gr. water.

The .416 Rigby is listed at 132.56gr. and the WTBY should be about the same as the .416/378, at 140.8gr. water. The .416 Remington should be about 108gr., same as the .416 Barnes Supreme.

The .416 Howell, using the .404 case necked down with a shoulder diameter of .515" and OAL of 2.55", is listed at 100.78gr.