Question about fillers for 45 Schofield rounds

[Diamond Curly SASS#57086]

I received the Cowboy 45 brass and the 160 grain bullets. I loaded up ten rounds using 15 grains of FFF APP and was very happy with the results. Weather here in CO has not allowed me but one trip to the range so I can try out 14 grains of real black under the 180 grain bullet in the 45 Cowboy brass and 25 grains of black under the 180 grain bullet as well. I did try one load of 15 grains of black with 12 grains of corn media and it clocked out at 425 FPS but wanted at least 500 fps so  when it warms up over 32 degrees I will see how that works. I have some loads with magnum primers to see if this changes anything as well. I appreciate all the input so will post results soon I hope. I really prefer the real black but if APP feels best that is what I will shoot. DC