Rather than trying to finangle some downloaded super recipe, you may just want to pick up a few boxes of .38acp ammo from Graf's:
Cheaper than .45acp ball, don't ask me how those economics work, but I'm glad for it. They shoot nicely in my 03 Pocket Hammer.
My Colt WWI reproduction has a copper-colored firing pin. I don't know if it's actual Cu/Be or just a coating so that it looks like it is, but either way it works and looks neat.