What's it there for?

[bamabiker]

I went shooting today and took my M625-3 and a couple others. When I got home I decided to go a head and clean the guns I shot. I started with the 625 and since I had never taken the side plate off this gun I decided it would be a good time to see how it looked under there. It was a little dirty so I started taking it a part to clean everything.
Now for my question, when I removed the rebound slide and spring there was a small pin inside the spring. It's about 5/8" long and 1/16" in diameter. It just fell out when I removed the spring from the slide. Can someone tell me what's the purpose of this pin?
I did put it back when I put the gun together and everything test fine. Other guns I've taken a part did not have this pin and I was just wondering what it's for and when did S&W start putting them in.
Any info is appreciated.

 

[john traveler]

That pin limits the rearward trigger movement and functions as a trigger stop. Some N frame models have them, some do not.

 

[cgt4570]

It's possible that it was factory, but most likely added by a previous owner. Serves the same purpose as the screw-adjustable trigger stop on older K target frames.

 

[bobelk99]

Maybe this schematic will help:

Schematic for Smith & Wesson® N-Frame 625-3 - World's Largest Supplier of Firearm Accessories, Gun Parts and Gunsmithing Tools

 

[bamabiker]

Thanks for the quick answers.