I started shooting BP C&B in 1969 with a Navy Arms 1851 "Reb" in .44 cal
There was a lot of good information in gun magazines and available from Dixie Gun Works and Navy Arms.
Then I measured powder as I do now and seated the ball to compress the powder. What was different back then was no wad over the powder. I put Crisco over the chambers but it all melted after the first shot.
I never had a chain fire.
Sometmes the Internet makes things worse