Help! Identifying right hand versus left hand threaded ejectors.

[Early Bird Dave]

I have read many threads, but am trying to get a more definite answer. Since Smith & Wesson did not always follow the rules, just wanted to confirm the visual inspection of the extractor. Is it true that left threaded extractors have a channel cut below the knurl knob?
I became interersted in this after reading some of the 29-1 model threads.
First picture is an N frame with a channel cut. Second picture is an S series frame without the channel cut.

 

[OFT II]

If there's a small groove behind the knurling it will have left handed threads.

 

[Early Bird Dave]

Thank you!

 

[Early Bird Dave]

One of the reasons I was asking, is this gun. I will have to suspect that someone changed the ejector out since this is a model 57 produced approximately 1972. Must be an ejector from a Model 29 or other?

 

[DWalt]

On some rods, the groove below the knurling may be fairly skinny and one might wonder if it is a groove or not. And sometimes they are much wider. But if there is a groove, it indicates a LH thread.

 

[Doc44]

The extractor rod in post #4 has a relieved area behind the knurled tip (albeit small) and has a left-hand thread.

Bill

 

[Early Bird Dave]

Thank you for helping out. I could see the channel cut on some And the tiny grooves on others.

 

[mh51]

So....is the second pic in the original post also a LH thread? It appears to have the small groove behind the knurling. It appears to be from a later "S" serial prefix, since the serial isn't stamped inside the ejector shroud.

 

[Doc44]

The revolver shown in the second photo has an extractor rod with a right hand thread (no machined area behind the knurled tip). Also, routine stamping of the serial number on the rear surface of the cylinder and in the extractor rod shroud was discontinued in May 1957 when the Soft Fitting Department was eliminated by S&W.

Bill