banzaibird:
The .405 load listed in the Manton catalogue is a 300gr bullet over 52gr 'smokeless' powder for 2,204 fps MV and 3,235 ftlbs ME. It was cropped because my home scanner is only A4 and the catalogue is 'foolscap'.

The spade doll's-head with crossbolt is indeed fairly rare, which is why I posted it as an interesting 'extreme' example of a third fastening.

bulldog: there is a very good discussion of the .405 Winchester cartridge and its applicability for big game over on the 'Big Bore Rifles' forum: click here.