This is what I was looking for. For some reason, Google didn't sniff this link out for me.

The reason for my inquiry is that I am trying to make some sense of the various rifles that Col. Corbett used in career. Fairly late in his career, he mentions the use of a .450 rifle: First, for the Rudraprayag leopard (1926); Second, for the Bachelor of Powalgarh (1930). It is possible that he actually used his .450/400 Jeffery, but an editor or someone else changed it to .450. If it really was a .450 rifle, what was it and where is it now?