This is a great write-up. Thank you very much!
Here is my experience with cleaning up the inner workings.
Components are listed in Bold and refer by name the way Taurus lists them in the manual.
I started by field stripping the gun and placing an o-ring around the trigger to fully disengage the Trigger Safety. I found that it was not always fully disengaging while pulling the trigger at some awkward angles to assess the gritty points.
Fully disassembled and cleaned everything very thoroughly. This was great practice to see how everything goes together and interacts with each other.
Completely reassembled and rechecked. I did not put the pins back in. The main assemblies were a nice tight fit in the frame and I felt this would not be an issue. This helped a ton with fitting and refitting everything to keep checking along the way.
I used a combination of needle files, fine Silicon carbide "Fine" and Arkansas stones as well as 320 and 800 grit sandpaper and metal polishing paste.
By putting light sideways pressure on the Trigger Bar towards the Central Support casting I found this to be a very large source of grittyness. So I decided first thing to tackle was the friction in the Central Support Assembly.
*Stoned the inside of the Trigger Bar where it contacted the Central Support casting and the casting itself where they meet through the length of travel.
*Stoned the sides of the Central Support Bushing (trigger bushing) flat and square to the Internal Support Central Pin. Chamfered the ID ends lightly and then polished the ID with a #38(0.1015") drill chucked backwards with metal polish on the shank. I found this bushing to be a real mess.
*Stoned the Trigger Bar where it rides on the Mechanism Support and Slide Disconnector.
I really did not do much in the Mechanism Support Assembly except:
*Stoned sides of Sear and polished inside Mechanism Support where Sear and Trigger Bar ride.
After I was happy with how the lower end was working I started into the slide. Yikes. In short, every automatic safety mechanism on this gun adds a significant source of friction. I hadn't anticipated the slide adding so much to the issues.
Alphonse from Lakeline describes the issue with the Firing Pin Sleeve (striker guide) perfectly so I will not explain that again. It's a known quantity so I just remozed the whole Firing Assembly from the slide to assess the rest of it.
There's obviously some serious friction between the Trigger Bar and Firing Pin Block. This can be found by removing the Extractor and associated components from the slide. With the Firing Pin Block out you'll notice there is now no interaction between the trigger action and slide mechanisms. So to address these components:
*Chuck the Firing Pin Block up in a drill so that the domed side is sticking out. Mirror polish this dome with a combination of fine sandpaper and metal polishing compound. You will want to remove all radial machining marks and linear grooves previously worn in by the Trigger Bar. You'll want to smooth out the radius of the dome but do not change the height of the dome or the radius. Doing so would mess up the timing of this safety. It is intended to unblock the firing pin just before full trigger pull.
*Deburr the hole in the slide that the Firing Pin Block rides in and ensure it moves completely free.
*Go back and polish the Trigger Bar where it interacts with the Firing Pin Stop. This can be done with the Trigger Bar in the assembled gun.
Overall I am much happier with the trigger on this gun now. I am measuring an average 5 pounds 4 ounces trigger pull with my Lyman digital gauge. I did not record the measurement before modification.
For reference I took some more trigger readings:
Lower assembly only, trigger fully to rear: 1lb 9 ounces
Only Firing Pin Block removed: 5lbs 0 ounces
Only Firing Assembly removed, trigger fully to rear: 2lbs
Perhaps someone can take the same measurements before working on their gun.
I hope this helps someone.
PT111 Millenium G2