Originally posted by Fastbolt:
The trigger play spring helps keep excessive play out of the trigger when the pistol is cocked in single action.
Sometimes a particular gun might exhibit a click during the first part of the trigger's movement when the gun is cocked in single action. This is reportedly encountered more often in the .45/10mm models than in others.
The click is usually caused by a condition where the front hooks of the trigger's 'ears', or prongs, have slipped up and forward over the top of the drawbar head's V-notch (in which the prongs normally sit). The clicking noise is usually heard as the tips of the prongs are being snapped back down over the edge of the drawbar's head at the top of the notch.
Most folks won't notice a 'sloppy' single action trigger when normally shooting a TDA gun. I had a trigger spring break in one of my guns somewhere during the course of shooting over 800 rounds and I only realized it when I was examining the gun while cleaning it.
The older trigger play springs were firmer and had two distinct prongs. The newer springs are lighter (more flexible) and are connected across the top.
Breaking off one side, or both, from repeatedly 'adjusting' them ... looking for that "perfect" single action trigger ... will require that the spring be replaced. It's a simple replacement, installing a new spring in place on the drawbar with a rivet, but it requires some familiarity with the design in being able to properly detail strip & reassemble the frame.
I've seen more than a few trigger play springs unintentionally broken by folks "industriously cleaning their guns", forcing the small end of brushes down inside the frame and bending/breaking off the the springs.
FWIW, cocking the hammer of a field-stripped frame will not only allow more access to the frame around the top of the magazine well for careful cleaning behind the trigger window, but it will position the drawbar forward, which can shield the spring, somewhat, from some well-intentioned but unaware cleaning efforts.
Armorer are taught to check the angle of the trigger play spring to make sure it contacts the rear of the trigger's prongs and reduces excessive play in the trigger when the trigger is all the way to the rear. If necessary, the small end of a wooden armorer's wedge is used to gently tension the prongs of the trigger play spring forward.
Armorers used to be taught to check for this by taking an EMPTY gun they were inspecting, cocking the hammer into single action, tipping the muzzle straight down and then gently checking to see whether there was excessive forward movement of the trigger under gravity. Gently checking the amount of 'wiggle' present pressing the trigger to the initial take-up point and then allowing gravity to pull it downward.
Here are some clickable thumbnails of drawbars with the springs attached,
The first pair are pictures from a manual and show the typical angle of the spring as used in guns.
The next images show a trigger held in the drawbar head as if it were in the gun, pulled to the rear, with the spring normally contacting the trigger prongs; and then 3 different drawbars and the normal angle of the springs as usually seen. These angles would probably work in most guns, although a minor adjustment might be found appropriate in an occasional gun.
Repeatedly bending and adjusting a trigger play spring is a good way to risk premature breakage.
None of this info should be taken as a 'how to', but as informal info intended to hopefully more clearly explain the function of the trigger play spring and its relationship to the trigger.
