On double actions the full circumference ring comes from closing the cylinder without indexing it then rolling the cylinder till it locks.
Eventually you get a fully ringed cylinder. Easy to prevent if you want.
With most double action revolvers, when you pop open the cylinder the bolt is already in the up position. When you then close the cylinder, the bolt will be bearing against the cylinder in whatever position the cylinder happens to be in when it is closed. Any subsequent rotation of the cylinder to latch it up will result in the bolt rubbing against the cylinder. We had a big discussion here a few months ago about whether or not this constituted 'abuse' of the gun. Personally, I feel it is completely normal for a double action revolver to be treated this way, it is not abuse. Double actions are simply different than single actions.