I’ve used 6 grains of Unique power with a Lyman 225 grain cast round nose bullet for years.Works well in every gun we’ve tried it in,including MAC 10s and Thompsons.
power=powder.
Boy when I started hand loading over 40 years ago, 6 grains of Unique was a common load for a lot of different calibers and bullet weights.
For instance in 9mm, 6 grains of Unique with a 115 grain fmj. 6 grains of Unique with a 255 grain cast lead bullet in .45 Long Colt. Same with the .44 special, and several others.