I bought my first .45 LC, a NMBH in 1973 and have loaded for it (and other guns so chambered) ever since. While I have loaded plenty of jacketed bullets I have shot far more cast. For "factory level" loads with 250-255 grain cast I burned many pounds of Unique; for heavier sub-Ruger loads BlueDot worked great for me. I had no desire to load to 30,000 cup, the little 4-5/8" Ruger was too lightweight and recoil unpleasant. Even during the 27 years I lived and hunted in Alaska I never felt under-gunned with a 250 to 300-grain cast at ~1000 fps.
Over the years I have tried other powders, especially when there were shortages. Universal, W231, AA-2, AA-5, HS-6, all were "okay" but the best accuracy with cast was consistantly with AA-5. 90% of my .45 cast loads today are with AA-5 and BlueDot. But I still keep a pound of Unique around just in case.
I always had better luck with softer alloys. Never measured thr BN but most were straight non-tempered wheelweights. All were a slip fit in the chamber throats.
.
.