WOOOOO-HOOOO!!! I FIGURED IT OUT!!!
Sorry for the outburst, but this was my first attempt at a home trigger job and it was a total success!!
Basically it was the exact same problem that was described in the thread that @Rover provided a link to (here: https://rugerforum.net/ruger-double-...e-threads.html
). After my previous post, I performed a more aggressive filing of the double action trigger sear (or the “lower shelf” of the trigger) by wrapping some 1000 grit sand paper around a butter knife and sliding it between the upper shelf and the lower shelf. After reassembling the revolver, I immediately noticed a slight but definite reduction in the “hump” I described! I performed four iterations of the same process (disassembly, sanding, reassembling, dry firing), and by the end, the hump in the DA pull was barely perceptible! I decided to leave it at that, since I have actually started to like the slight hump in the trigger pull (also I was starting to worry that I was pushing my luck). I did one final disassembly and polished all surfaces with 2000 grit sand paper and then reassembled. The DA trigger pull is now AMAZING, and I appreciate it even more because I feel like I was able to “tune” it to exactly my preferences through this iterative process. The tiny hump actually makes it easier to stage the trigger (which I like to do for precision shots), but I can also effortlessly “pull straight through”. Also, the polishing of the hammer dog and upper trigger shelf seems to have made the DA pull even smoother (Although I did also polished just about every mating surface I could find!).
I came up with an interesting idea that helped me visualize the exact engagement of the trigger and hammer during the DA cycle. It’s hard to describe, but I included a picture below show it. Basically, you can attach the hammer to the OUTSIDE of the frame by using the hammer pivot pin, and then push the trigger assembly up against the bottom of the frame, but with the right side edge of the trigger assembly against the left edge of the frame. The end result is that the trigger and hammer are in the same relative positions as they would be inside the revolver, but they are plainly visible. With a little practice, you can actually operate the DA trigger pull with the parts on the outside of the gun. This experiment is actually what convinced me to file the DA trigger sear, as I could clearly see that it was engaging too early in the cycle! I’ve also included a few other pictures showing some of my polishing work. Unfortunately I forgot to take close up pictures after I finished the final polishing of the DA sear and upper shelf of the trigger, but I was able to achieve an almost-mirror polish.
Thank you so much @Rover for all your help, and to everyone else who contributed. This was an extremely fun learning experience, and I’m very glad I went through with it. For anyone else experiencing a similar problem with their security six (or sp101 or Gp100), I would highly recommend trying out this solution. By the way: it’s worth noting that “factory new” hammers and triggers can be bought on Numrich at the moment for around $25, and hammer dogs for only $3 or so, which is part of the reason I chose to dive into this trigger job process right now. Might as well give it a shot when replacement parts are available and cheap!
Thanks again to everyone, and feel free to ask me any questions you have.