rifles for this cartridge were made in germany and britain probably by any maker one time or the other up to the 1920s when it became obsolete. as a blackpowder round it was relegated by the 9,3x72R in germany in the 1890s because the 9,3x72R hold more powder when loaded with black powder and later with nitro it get a higher velocity with less pressure because of the bigger case volume.
anyway, 9,3x72R brass is a good starting point to make x57R brass.
the bullet for the 9,3x72R is the very best for the 9,3x57R 360 because of its construction.

This is a TESCO ( Teschner-Collath) bullet which was designed to give the lowest pressure( resistance) in the barrel and work best with the velocities you get with this cartridges. you have to slug your barre, if very tight .357 bullets will work.