Howdy
Trigger stops were pretty much limited to K frame target revolvers with adjustable sights. I have never seen a trigger stop on a S&W 'service' revolver with fixed sights, such as a Model 10, although I suppose I could be wrong.
For the purposes of this discussion, we will define a 'target revolver' as one with adjustable rear sights, as opposed to a 'service' revolver which did not have adjustable sights.
These were the days of Bullseye competitions.
A law enforcement officer was most likely to carry a revolver with fixed sights, such as a Model 10. He did not want his revolver to fail to fire in a pinch because the trigger stop might have gone out of adjustment. Not the end of the world if the trigger stop got out of adjustment during a Bullseye match.So service revolvers did not have trigger stops.
Trigger stops were set at the factory so the trigger just had a very small amount of over travel.
This is a photo of the frame of a Model 17-3 that I bought brand-spanky new in 1975. The trigger stop is a small 'teardrop' shaped piece protruding slightly into the space behind where the trigger would be. It sits in a small slot cut into the frame. The trigger stop is held in position by the by the small screw in the photo.
As far as I can tell, I believe S&W K frame revolvers began having trigger stops installed with the K-38 Masterpiece. This model was first released in 1949. This is a photo of the lockwork of a K-38 from the 1950s. The trigger stop can be seen just behind the trigger.
I have checked several of my N frame 'target revolvers' (with adjustable rear sights) and none of them has a trigger stop. This 44 Hand Ejector 4th Model does not have one.
At some point, S&W stopped putting in trigger stops. I forget exactly which year this Model 617-6 was made, but despite the fact it is a K frame 'target revolver' it has no trigger stop.
Would you please describe how to adjust a trigger stop?
My advise is leave it alone, don't mess with it. It was set at the factory and there is no reason to mess with it. To tell you the truth, I don't recall now whether the little screw goes through the trigger stop, or if it just snugs up against it. I can tell you that when I tried to adjust one a bunch of years ago there was much gnashing of teeth as I tried to get it positioned just right. The assemblers at S&W adjusted them just right, they did it all day long, and they could set one properly in probably just a few seconds. I have quite a few S&W 'target revolvers' with trigger stops, most of them are at least 50 years old, and none of the trigger stops has ever moved. They were adjusted just right at the factory and I will never try to adjust one unless some kitchen table gunsmith has messed up the adjustment.
Model 17-3
K-22 Combat Masterpiece.
K-22 Masterpiece.
K-38s.
Model 14-3
Model 19-3
K-32 Masterpiece. Notice the box says ANTI-BACKLASH TRIGGER! That is referring to the trigger stop.