Over the years I've fired a lot of accurate revolvers. One of my main goals as a reloader was testing and developing accurate loads for my guns. I had a 6 inch model 19-3(IIRC) that was consistantly accurate with a bunch of different stuff. Same for a couple of model 27's and a 28. Generally speaking it was much tougher to develope revolver loads that were much more accurate than factory ammo, out to 50 yards. Although it's tougher to beat factory centerfire rifle now, back in the days it was a lot easier.
Anyway, back to the answer. The most accurate revolver I have ever owned or fired is a 44 special that I purchased from a forum member from Tenn. It is a former GA State Patrol model 28-2 that was converted to 44 special by an unknown source. It has what appears to be a model 1950 6 inch blue bbl and a re-chambered cylinder. It was evidentaly well worn as a patrol gun and it has been refinished at some time and has become less than pristine once again. But don't judge a book by it's cover because this baby will shoot! Except for cosmetics it is in great mechanical shape. I've made a believer out of more than one that doubted it's exceptional accuracy. I've been offered a great deal more than I paid for it, but this gun ain't going nowhere! I've learned my lesson, I hope. No more sellers remorse for me.