I have a .54 caliber T/C Renegade. The max load according to the book is 120 grains of black powder. I have never seen a need to shoot that much because the accuracy goes down the tubes after 100 grains.

I shot almost anything I could shove down the barrel in this rifle. The best stuff for shooting in my rifle is;
Speer .530 roundball, .015 cotton pillow tick patch, wonderwad, and 80 grains of Pyrodex Select
300 grain LEE R.E.A.L. conical lubed with bore butter, wonderwad, 90 grains of Pyrodex Select
430 grain T/C maxiball, wonderwad, 90 grains of pyrodex select

I am making some new conicals to try. They are 380 grain LEE R.E.A.L. conicals. I want to lube them with bore butter also, and then try and work up a load with some Triple Se7en ffg powder.

I shot some sabots a friend had, and it shot them alright, and I was sure I could have worked a load up with them, but I really did not want to get into the plastic in the barrel problems I heard so much about, and besides it shot the other stuff so well, and knocked down anything they hit, I saw no reason of get high tech with the thing.

You got a great shooting rifle there. I have hunted with mine for over 20 years, and it still knocks them down everytime.