I found my notes on the 43 Span RB.
Used blown out 348 win brass
387gr cast bullet from a Rapine mould as cast. 50:50 lead/WWs
16.5 gr Unique, tuft Dacron over powder
Win LRP
MV = 1350 fps ( according to book) I think this came from
Cartridges of the World by Barnes.

Never hunted this gun other than plinking a few ground hogs
but I wouldn't have been afraid to use it on deer. Don't forget
this is on BP action so stick close to book with smokeless.