I can't speak to #9 as I have never used the powder. Over the last 35 years I have loaded a lot of 44 Magnums with 2400 and W296. The older 2400 was quite dirty but it was changed a number of years ago to a much cleaner formulation. It also depends on loading density as to how much residue and unburned powder is produced. I like 2400 very much.

__________________
Dick