Before I take a weapon apart, I clean my bench, the floor, and I keep all my tools in the tool chest above the bench. Each part removed is placed in a parts holder. I only work over the bench, not near the floor and that is where the part landed when it fell out of the trigger area.

The steel part has a special letter stamp just identical to the other parts of the Sigma so I know it belongs with the Sigma.

This part looks identical to the slide release however the slide release has been accounted for, and this does not have a notch, or groove in it..

My Smith & Wesson manuals are really in depth, however this is brand new and it may have a new part installed after this take down manual was produced.

I have taken about 15 weapons apart in my firearms collection (I still have more to service) and I have photographs of each part being removed from start to finish. I am really careful not to make a mistake. I was following the take down manual with each of the parts I removed from the trigger area when this piece fell out and that was the one not in the take down manual.

Now I will have to admit that it was a surprise to see something that was not on the take down manual, fall out of the trigger area after I went over and over the take down procedure before I started. I looked over all my photographs to see if it was in them and I cannot find the part anywhere.

Is their a person who knows where this part fits in the trigger area of my Sigma?