I've owned a bunch of original '76 carbines in all calibers, including .50 Express. The .45-75 has always been a favorite. I took my son-in-laws out last weekend and let them shoot a .45-75 carbine and a .50 Express rifle. What a blast. I never use smokeless in any of my original 76's. You are asking for trouble. In the .45-75, I use 4.3 grs. of 4227 on the primer and 67 grains of 2F black, with a card wad on top. My cases are reformed 348 Winchester, so this is a compressed load. I use ONLY 350 grain bullets with SPG blackpowder bullet lube. The blackpowder lube and the 4227, help keep the fowling down considerably. Always use soap and water to clean the bore and turn the gun upside down with action open and carrier block up, flush with the bottom of the receiver. Much easier to clean and no residue will drip into the action, if done right. Good luck and have fun.