I feel it now that I know it is there.
I did not before and I find that these data have already educated my finger. It is curious in a very good way. Fine, new data is like that.
I found it supremely satisfying intellectually to be able to “see” and thus better comprehend what my finger “felt” and my mind “understood”: the confluence between knowledge of mechanical complication, subjective feel, and objective measurement.
For the big, DA movement of the Mountain Gun’s curve, one can see where ratchets and levers move, cylinders turn, stops engage, etc. where the dips and peaks occur.
“Crisp” triggers which are SA are described by very simply shaped curves with low, flat initial force but then rapidly rise (steep slope) and then drop. This is directly related to the trivial mechanical action occurring which only involves breaking the sear after a simple camming action.
The curves do reflect the mechanical actions occurring.
“Mushy” triggers like those with Glocks and the Ruger LCP seem to be curves which require increasing force all along its travel (similar to DA revolvers) but which exhibit steps or flat spots while it increases until it flattens for a few mm before the sear breaks. This is related to the modern polymer pistols’ use of trigger bar mechanisms.
Interestingly, the adjective “wall” used to subjectively describe the final stage of Glock trigger travel that has to be overcome with more trigger pressure connotes or implies the feeling of an increase in the amount of force required in the last bits of trigger pull before the break which one would interpret to be a very rapid rise in force required before the sear is tripped. The measurements show that there is no very steep, barrier-like slope of force here that is a “wall”. The “wall” is instead a plateau of force with distance and is more appropriately described as a “pre break flat spot”. The adjective of a “wall” of force versus distance actually more appropriately describes a SA trigger!
What is also very revealing to me is how much the shape of the curves seem to matter more to my finger than just the absolute value or maximums of the poundage may relate. Maximum trigger weight values are not very important it seems because I do love me some Mountain Gun DA trigger and I shoot it quite well.
Once we know how to read these curves, we develop a better and fuller understanding of what comprises good and bad triggers. One can already herein state that an “ideal trigger” may be one whose force versus distance curve is a simple spike or a very narrow width rect function.
Even with that said, the “shape” of my SA USFA trigger looks more like a very small “glock-like curve”.
Perhaps by “crisp” we mean triggers that are short to break once we perceive increasing force in the pull and those that are mushy are ones which require continued, sustained increasing force to pull - which is why a DA revolver’s trigger does not feel mushy.
In this vein, I think the derivative (or local, incremental slopes) of the F vs D curve can more properly describe a trigger in how it relates to what we actually feel as “crisp vs mushy.”
A simplified cartoon of what we perceive with our finger...
