You can use Unique which should burn cleanly enough if loaded to the right levels, WW231, Bullseye, Red Dot. From my old manual 6.5 gn of Unique will bring the 230 gn cast slug to the velocity you want, so will 4.7 of Bullseye (max load); WW231 uses about 6.1-6.3 gns to get you to 850 or so and Red Dot uses 5.3 gns to get you to 880.
I bump my Unique loads up a hair to 6.7 under the 238/240 gn Keith style swc designed for the 45 Auto Rim or 6.3 of WW231, with both charges getting up to about 875 or a bit better. My manual(s) show the Unique loadings at below max and the same with the 231. Hope this helps.