Have not fired my revolvers for about 3/4 years, but started shooting them in the late 1960's. Started when I was about 16 with an original Rogers & Spencer .44 (that I paid $125.00 for from a high-end gun shop and wish I had it back) that was in probably unfired condition as was common to find - at least then. Being a teenager with no protege, I loaded all 6 cylindres with powder and wadded paper for "blank" loads. As you can image my first shot turned out to be a 6 shot volley gun. LOL Scared the peewaded out of me. Cleaned the gun and put it away.
Later in the early 70's purchased one of the Italian brass framed Griswold .44. But bought some of that swaged .44 buckshot packaged in the gunny sack type bags. While the balls fit in the cylinder, they were not snug enough. Even with Crisco on top I got a chainfire at the range. DARN.
Fortunately for me, the same day at the range I met a gentleman about 20 years my senior that was familiar with black powder firearms. After seeing my loading material and procedure he properly briefed me (somewhat like a sergeant). So the right size balls were ordered from Dixie. No more chain fires.Turned out to be a great friend.
Later on, started shooting the original R&S - loaded correctly - and no chain fires. Took a .454 ball if I remember correctly. (That pistol was really accurate.)
In these later years, I have 2 1860 Army .44's and a 1851 .36 Navy that I have shot off and on through the years. No chain fires. I do like using the felt wads between the powder and ball. When the swaged ball leaves a nice even lead ring on the cylinder mouth I know I have the right fit. Don't even use any grease on the chamber mouths.
Full admission: The revolvers are the only black powder guns I prefer shooting with the imitation black. I still have a supply of Clear Shot from many years ago, most in unsealed plastic containers. This became Clean Shot later on (or vise-versa) and later I don't know (?) What I like is that I could shoot what seemed like the entire day without disassembly. Just cleaned it when home. I could swear that it burned cleaner than some modern powders. Don't know what I'll use when my Clear Shot supply runs out. LOL
So I'll quit blabbing away here. The moral of my story is I've only had three chain fires all due to operator error and ignorance.
Rick