I started loading for the .45Colt back in 1975 when I lived in Alaska, I had a Lee mold for the .45-70 that produced a 340 gr. bullet, I sized those down to .452, and loaded them over a generous charge of H110. Those were my bear loads. I was given a Lee 255 gr. RNFP that I loaded over 9 gr. of Uique, that was pretty close to the old standard .45Colt loading. I read an article about the RCBS 270 SAA bullet and had to try that out. My load with that bullet, in my alloy they are 289gr, over 9.5 gr. of Unique, those are very effective on deer.
As I have gotten older, I find that I enjoy shooting lighter bullets in the .45 Colt and my current favourite is the Lee 200gr. RNFP, I use those in my Redhawk and they work well with speed loaders.