Back in the 1960, I experimented with just about every powder available in my .45 Colts. After all was said and one, I settled on 255 grain fairly hard cast SWC bullets and 8.0 Unique for my standard load. If I wanted a bit more, I bumped it up to 9.0 of Unique. The 9.0 load was in Ruger and modern S&W weapons, not original Colts. I still use those loads today.