Originally Posted by
gaijin
Mainspring controls the force which hammer falls, as well as retards the slides rearward movement in recoil.
Too little tension on the center leg of leaf/sear spring will cause a slower, lagging RESET of trigger, which may feel “mushy”.
Simply increasing tension on center leg will provide a more positive reset, but will contribute to more weight of the felt “trigger pull”.
Both the Mainspring weight and the sear spring “legs” control weight of trigger pull.
The quality of the interface between sear (nose) and hammer hooks is responsible for the “felt” part of trigger/hammer interface, or trigger “break”.
Shit MIM parts can be a source of a “lousy trigger”. It is much easier to get a “good” trigger on quality parts (think EGW, Harrison, Wilson). It’s possible to get a decent trigger job on MIM parts, but usually much more difficult than simply starting with quality parts.
It’s a fairly fine balancing act to get a nice, “light” pull while maintaining 100% function and not beating gun to death under recoil.
Describing a “mushy” trigger is really subjective. Truly one of those “really need gun in hand” to properly diagnose the issue.