Good day to all...
Of the several S&W revolvers I have owned,only my most recent 686 has had the loosening issue.You can tell it's loose when the cylinder gets difficult to swing open.I discovered a 2 dollar method that works great & allows the ejector rod to be tightened properly without damage:a 1/4 brass compression fitting.It fits the ejector rod perfectly and allows you to use a wrench to tighten it.BE MINDFUL of over tightening though.I put empty brass in all 6 chambers when I tighten.I recommend splitting the ferrule in one place to make for easy removal.Works great in a pinch.I keep one in my shooting case now, but haven't needed it since tightening it properly.Proper tool is on the way to me.I don't recommend loctite either.