I also have the .50 T/C Hawken cap, and love the gun! After experimenting with different loads and conicals I found my gun likes 75 gr 777 with the 275gr maxihunter the best. I shoot nice groups at 50yds with that combo. When shooting patched balls, I have to back my powder loads down to 60grs, but still shoot decent groups at 50yds. Maybe it was just me, and probably is, but I noticed when I tried the heavier 370gr. maxiball my groups became significantly larger at 50yds, not exactly confidence inspiring. So I am sticking with the 275 gr maxihunter since my gun likes them and I know where my shots will hit. Good luck, and finding the right load and bullet for your gun is half the fun of muzzleloading.