So you're shooting a patched round ball 50 cal. Your rifle will either like a 490 gr ball or a 495 depending on the bore tightness. I shoot .10 pre-lubeb TC patches with a 490 round ball and 90 gr of 3F black powder. If you have a really loose bore a 495 ball may be needed. One important thing to look for when shooting is retrieve some of the patches that have exited the barrel and check for burn through. You should have a patch with no holes and the rifling marks clearly on it. Using pre-lubed patches like those from TC you should not have any burn through. Patching thickness will be determined during the loading process and seeing how hard the combo loads and getting acceptable accuracy. A good tight load, still loadable though will normally shoot more accurate than a loose load combo. Seat each load consistantly with moderate tamp, don't need to crush anything. 2F powder was generally for 54 cal and above.