Hello Kenny, If I am telling you something you already know please forgive me. In looking for a S&W 66 look closely to the forcing cone for cracks at the bottom, rare but has happened in 66's due to so many of them was service weapons and had a steady diet of .357 ammo. You can also tell if one has had a lot of .357 ammo if above the forcing cone on the top strap there is a cut from "flame cutting".
Some of my terminology may be off but you will get the idea. I will watch for a 66 for you, I had two sold them and moved into a 686 4", stronger frame and can shoot +p if ever a need. Take care, Rich
I appreciate the info. The only reason I am looking for one is that is what the Sheriffs Dept carried and I have a side plate with the Sheriffs logo engraved in it. With a 66-2 I can replace the side plate and have a Duty Weapon to pass on to my kids. I have a couple other 357 but only shoot my Ruger GP100 that I have done some work to