Got the 24C installed and test fired today. Installation was straight - forward but had a little trouble with the toggle springs assembly. Fixin' to cuss. One of those deals I later determined where you do better when less focused / trying too hard.
In the vise I had a big issue dry firing. I would hold and "walk" the hammer forward when pressing the trigger. Sometimes it would fire and other times it wouldn't.
When it wouldn't it had what felt like a solid 1/8" of pre-travel. When it fired it had none. I finally noticed when it wouldn't fire it was due to it not resetting as I pulled the hammer back.
When it functioned properly, I would cock the hammer and it had the slightest reset sound approx 1/2 second or so after cocking. I used the KNS 15-22 pins and thought perhaps they were too tight. Loosened them and it made no difference.
Looking at it all, I thought the polymer walls thickness might be causing a rub of springs, pins, whatever. The assembly came drowned in oil which I had wiped down well. I thought it was preservative due to its stickiness. Called Hiperfire and they told me it was oil. Oiled up what I could with it being fully installed. I manually worked the hammer back and forth a zillion times.
The problem still happened but not nearly as often. Perhaps 1 out of 10 as compared to 1 out of 3 or 4. I said screw it and took it out back.
Fired 25 rounds slowly with no issues. Fired an additional 25 as quickly as I could. No problems.
Conclusion:
I feel the assembly as a whole when using the lightest pull weight toggle springs is very sensitive to external pressures such as holding the hammer, cocking it manually, etc. Goodness, those lightest pull weight springs sure make the hammer difficult to pull back. Not really difficult but a truck load of more pulling power is required to pull the hammer back. When the trigger is pulled, the hammer flies. I don't anticipate any light strikes.
The lightest pull weight is advertised at 2.5lbs. Before installation I tested the factory trigger which has been excellent. I used only my digital pull gauge and did 6 pulls. Average was 4lbs 6oz. Excellent compared to several I've read about.
Did same with 24C. It was jumping all over the place. From just a spit under 2lbs. to 3lbs.
During my live fire, I stopped at 15 rounds, put the rifle in my lead sled and averaged 1lb 6oz on 5 rounds. Brought out my old style gauge and it showed 1 1/2lbs to just a hair more than that. Definitely light but didn't feel dangerously so. I noticed zero take up and you would have to know the trigger resets because I couldn't detect it. Perhaps if you were live firing for the sole purpose of determining reset you might feel / hear it.
Did not install the optional shoe.
Assembly appears to be very well made. Customer support was quick to answer the phone and answer my question. Not knowing how easy it might be to contract or distort the polymer receiver with the anti-roll pins, I might consider the Colt 901 "normal" pins which are longer so that they don't sit recessed as the factory pins do. Can't believe S&W used the regular length pins on these polymer receivers.
Based on my short term experience I'd recommend the 24C.
