Howdy All:
I just bought an antique (1882) Westley Richards double rifle in 577/500 number 2 BPE. There is nothing that I can see anywhere on the rifle that would indicate what the regulation load is. Cartridges of the World show either a 300 or 350 grain bullet at around 1900 fps as a factory load. I have dies and Bertram brass. I have thought about trying some Blackhorn 209 under a 350 grain bullet, but I am hoping some of the more experienced members here might recommend something.

Texas Bill