You could do as suggested with the more expensive BH209. But if the T7 is working for you, then you might want to consider Pyrodex. Not as clean as BH209 but not as dirty as T7. You can also replace those sabots that come with the shockwaves with some Harvester crush rib sabots for easier loading. The come in black for .451" bullets like the SW or .45 cal pistol bullets or green for .429" bullets like the .44 XTP.
I've found that the sabots that came with the SWs were not consistant. Some would load easily and others would be hard to get down the bore.