I clean every time I come home from the range. All of my S&W revolvers blow hot lead and gases out that barrel cylinder gap. That 617 looks like mine did after a couple hundred rounds . All my k22’s do this , lead ammo is the worst, copper coated better .
When benching and you rest the front of the frame on the sand bag/rolled up towel you get instant knowledge of what comes out,like just as looking down range and seeing your group . 2 1/2” at 40 paces is cool ! Dental picks, small stainless brush for stainless, small brass brush for blued , and razor blade are mainstays in my cleaning kit . One thing I’ve become curious about in reading this thread is what do the revolvers look like that shoot lead free bullets(tin), or coated ones like cci made ? Happy shooting and cleaning !