To tighten loose ejector rod:
Unless I'm mistaken, a model 27 NO DASH will have a right hand thread on the ejector rod. The change to the thread direction occurred with the 27-1.
In this case getting the ejector rod tightened down will take a bit more fussing with. I would suggest that you find a piece of wood that is just thick enough to wedge between the hammer and the frame recess to prop the hammer open so that the cylinder stop is disengaged and the hand is a bit "loose" in regards to the cylinder positioning. This will allow a small amount of back and forth movement of the cylinder. Then it's a matter of pinching and releasing the knurling on the ejector rod so that you can work it back in by rocking the cylinder back and forth. Just be careful NOT to force the cylinder at either limit of travel, take it slow and don't try to rush it.
Now, a couple of notes that may be rather critical. First, most of us wheelgunners are getting on in years, I'd suggest that you use some reading glasses so that you can see exactly what is happening as you try and move that ejector rod in.
When you first start I expect that they will be enough drag on the threads to make it difficult to get it to move. The change from right to left hand thread was supposed to happen with the -1 change. However, S&W has a rather long history of allowing some mismarked revolvers out of the nest. Quite simply, just because it wasn't stamped as a -1 that's not a guarantee that it really is a no dash. If you get that rod to move just 1/2 turn for a right hand thread and if it doesn't start to ease, reverse direction and see if that helps.
If you can't get the ejector rod to move at all in relation to the cylinder, stop and just send it in for repair or have a local gunsmith who is trustworthy take a look at it. This is a situation that calls for finesse, not force and it's too easy to let yourself force it out of frustration. In addition there may be something else going on.
