A long time ago, I owned an 1851 Navy kit. The frame was brass and would not rust! I was very happy shooting it for a long time except that the caliber was smaller than that of some of my friends'. Then, I was told that my gun might be dangerous to use, that the issue was the brass frame. I decided to research the issue and found that:
If you shot it all day long, every day, the cylinder gap might increase in size from the cylinder recoiling into the brass frame and increasing the fit causing the cylinder-to-forcing-cone gap to increase and lose power. It might also burn your finger if you held it next to the aforementioned gap while firing! (Why in the hell would you do that anyway even if the fit was tight? Sometimes the "ring" of lead shaved from the bullet seating would come out of there in any gun!) Now to the meat of the subject: Forget the above. It is when the cylinder pin becomes loose and "wobbly" in the brass that the gun is not fit to shoot anymore. The cylinder may align itself with an axis other than the one that the bore is true to. The ball (not co-inciding) with the bore will send fragments in tangential directions. My ex-wife has such a fragment in her upper arm. I am thankful that was not brought up at the divorce. I have also found that brass frame revolvers and brass in general suffer the less from corrosion due to cleaning issues, and perhaps, get by with less lubrication than all-steel guns, in my opinion only.
"When you see the smoke on the wind, look for me."