Thanks again for all the information.
The Lightning I have was manufactured in 1877, first year of production. It is in great condition and locks up tight. I understand the best practice of using black powder for loading. However, I was hoping there was a load with smokeless that would be safe. Maybe Trailboss. I have some 148 gr hollowbase wadcutters I can use for bullets. They are soft lead and should expand into the grooves. They are left over from my Bullseye shooting days.
If BP is the only safe way to go, I need some advise on how to get started. Never have used Black Powder. Ae substitutes best? Need info on how to safely handle it and not get blown up!