Take the grips off and read the serial number off the bottom of the grip frame.

Open the cylinder and read the model and dash number on the frame under where the barrel comes thru the frame. Ignore any other markings on the yoke.

What is the serial number, model number, and dash number?

Show pictures of the markings on both sides of the barrel.

Knowing this we can better help you.

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~ S&W aficionado in training ~