I have used 4451 in my CA -10 6.5 creedmoor. I also have used- 760, hybrid100, 4166 & r-16.
The 4166 I used in 100 grainers. All the others were for 120gr or more.
After using r-16 I’m not sure if I would get any other powder for both my ar and bolt 6.5’s.
For my ar/CA I haven’t went above 140...