The front sight on my four screw model 10 no dash is about 1/16th of an inch wide while the front sight on my model 10-7 is about 1/8th on an inch wide. When did the sight change and why. Also the trigger on my 10-7 is smooth, not serrated like the model 10. Is that normal?

If you measure it you will find the sight on your Model 10 is .100+/-. No post-WWII S&W had the 1/16" sight. The change to 1/8" was in 1961 with the 10-3.

The smooth trigger, at one time referred to as the "Texas Ranger" trigger, was introduced on a Texas Ranger commemorative Model 19 in 1973. The trigger was available from then on and could be purchased as a replacement part. There is no specific "dash" when it became standard for the Model 10.

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Gunsmithing since 1961

Could be customized as well. Here's the front sight blade on my Victory Model:



It's 0.10" across at the aft end. In this case there was no real reason for the taper, I think the gunsmith was just showing off.

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