I have a J frame 360sc that has a separate ring (gas ring?) loose on the yoke when I take the cylinder off for cleaning. All my other S&W revolvers (K,N,J)don't have this ring loose on the yoke. Is this normal? The gun works great, I am just wondering about this loose part that the others don't have. I don't have a pic because I don't want to take it apart now. Thank you, Uvaldi.