I clean after every range trip, which is about 125 rounds. At this point, the crud ring feels like it is just starting to bind .357 cases. I have a slightly flared empty .357 case that I use as a scraper - it fits snugly when the cylinder is very clean. After 125 rounds, I'm wrestling with it once it hits the crud ring.

I use a .40 or .45 brass brush and take several passes with the crude ring pre-soaked with Hoppes 9 or Ballistol and even use a drill sometimes.... it still feels like it's being removed a molecule at time.

Perhaps I'm trying to get it too clean (where you can see the cylinder wall again), but I just have this fear that if I leave it, it will continue to build/grow and effectively petrify in there.

Everything else on the gun cleans up fine... it's just that damn 1/4 inch between the .357 & .38 case size that's driving me nuts.