Many moons ago (1968) I built a Colt 1849 from a Dixie kit (brass frame). I had a lot of fun shooting it but I loaded it to the max when I did not know better. The pistol began to get "loose" and rattle. On my last outing with that gun I had two simultaneous discharges one from the chamber aligned with the barrel and one from an adjacent chamber. On the next loading of the gun I had three simultaneous discharges one from the chamber aligned with the barrel and two from adjacent chambers. I stopped shooting, went back to the house and cleaned the gun and did an examination and found that the recoil shield had nipple marks from where the cylinder moved back and hit it. I retired the gun as a wall hanger. I did have tight fitting balls in the chambers with Crisco over them. I have not experienced any "chain fires" since that time. I do not believe chain fires come from the flash of the burning powder out of the front of the chamber being fired but from the rear - my personal experience. This is one reason why I don't buy brass frame revolvers - yes- I know that I was the cause of my chain fires by overloading that little revolver but this lesson sticks with me to this day, thank God that no one was hurt :bow: .