I've got a Knight Disc that I bought new about 8 years ago...I've shot it about 5-600 times...

With the Pyrodex R-S it likes a 250 T/C Shockwave and 90grs of powder...
or...100grs of the Pyrodex and the 300gr Barmes M-Z...

I shot the former for 3-4 years and killed 8-10 deer with and have killed about the same with the Shockwave...I prefer the Shockwave when field hunting as it shoots flatter...

In the .54 Renegade, for targets 50grs or so...Deer hunting 75-100 grs of the Pyrodex...