My most accurate revolver is my 480, not my .357, and the 480 will put a cylinder full into 2" or better at 100 yds, scoped from a rest. I have no doubt a good .357 will be capable of the same, and hence stretching out to 400-500 yds holding a cylinder full on a 10-12" plate should be no problem. Offhand, and exceptional shot should have no problem at 200 yds.
As far as bullets staying stable at extended ranges, it depends on the bullet design. Years ago I sent some 460 gr wfn's in .475" to a buddy down south to test in his 480. Just as I'd found, it would group a cylinder full into 1" at 50 yds no problem when launched 1100 fps. But he tested them at extended ranges and found they started flying somewhere beyond 200 yds. The 400 gr lfn's would keep stable as far out as he was shooting, which I recall was around 400 yds.
