My .50 cal 1/48 twist T/C Renegade shoots power belts really well at 200 yards and Roger Raglin had great results out of his with, I believe, Maxi Balls. What kinda distance you after? I never tried mine beyond 200. I put Williams sights on mine and got rid of the T/C sights. The front bead was just too course for my liking. After the eyes started to fail up close, I had it drilled and tapped for a scope and mounted a 1x scope on it, you might think it ruined the gun, but it was worthless to me not being able to focus on the bead. I had it zeroed at 200 and could hit a 9" paper plate every time, whether shooting PB or T/C ez glide 250's. it maintained a 4" group at 200 pretty consistently, not too shabby considering the 1x made the target look further away and the crosshairs were pretty coarse. Runs in my mind they are about 3moa. When you couldn't see the plate, you knew you were lined up.
I used to pack it and my White Whitetail every hunt I went on. The idea being the Whitetail zeroed at 100 and the Renegade 200. I always shot the Renegade first though cause it was in my hands and the Whitetail slung. I may have to put a better scope on it and try it at 3-400 yards. You have piqued my curiosity. I shot 777 out of it as well and it's the general notion, it doesn't do well in anything other than inlines. After I dropped the powder, I always leaned the gun towards the nipple and gave it a little tap. Whether that did anything or not, I have no idea, but it did go boom as reliably as my White. I have since switched back to Pyrodex Select in my White. Love to try real black but nobody in Southern Utah carries it, and I'm not about to pay hazmat fees to have it shipped, I have made my own black but I've only shot it in my sons .58 musket with round balls. I got into muzzleloading 38 years ago because it was inexpensive and gave an extra opportunity to hunt. My how things have changed.....