I installed these parts along with the ss hammer strut and Colt sear spring the day they arrived in my new Springfield Range Officer 9mm. I had to do some minor fitting on the thumb safety but that was it. The pistol, AFTER I cleaned up the original fire control parts, and before the Harrison parts,had a pull of 6.3 pounds. Worst trigger in our safe that isn't double action. Once the Harrison parts were installed and function/safety checked, the pull dropped by 2 pounds to 4.3 without touching the sear spring. Today I received my new Smith and Alexander mag guide and some new magwell grips. I installed with a 23lb. mainspring replacing the ILS system. Voila! The pull is now 3.5 lbs. with a crisp. clean break and short reset, again without touching the sear spring. I still need to adjust the takeup but I'll wait until the pistol is fully broken in.
Going to install my Dawson F/O front sight tomorrow then off to the range Sunday for zero and break in!
I am very pleased with the Harrison parts and the fast shipping. I'm sure I will be back for more after this experience.