Here's some info I found on
www.thefirearmsforum.com... I'm still looking for more stuff on striker springs. Please help!
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"I recently completed a trigger job on a PT111 Millennium. Never again.
The major problem is the machining marks left in the firing pin tunnel. Got those smoothed down. There are two springs, one drives the striker/firing pin forward, and one retracts the firing pin below the breech face allowing the gun to feed upward from the magazine during cycling. The factory FP retracting spring is a flimsy affair and with the least amount of set or deformation it will allow the striker spring to overpower it which results in failures to feed upward since the FP now protrudes slightly from the breech face. The retracting spring also has to push the FP rearward just enough for the cheesy little connector to catch it, which allows for repeated trigger pulls without racking the slide (that particular contraption by the way, is one of the most poorly designed mechanisms since the S&W 61).
Ended up making a new reduced-power striker spring and an increased-power retracting spring. DA pull levelled out at about 8 pounds with only a little grit.
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Here's another post from
www.thefirearmsforum.com:
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OK. On this particular gun (PT111 9mm), field stripping was almost impossible. Got the slide assembly away from the frame, but the barrel would NOT come out of the slide. The screw that holds the front sight on had not been trimmed correctly at the factory and was preventing the barrel being removed. Problem #1 fixed.
The Millenniums are DAO, but somewhat unique in that the trigger engages the striker every time you pull the trigger and is not dependent upon rearward movement of the slide to engage the bearing surface. On its face, this is a good thing until you look at how they went about it. There is a coverplate on the underside of the slide held by a screw. Underneath is a small, thin lever and an absolutely microscopic coil spring. Without a doubt, the cheesiest setup I've seen since the good ole RG days. If you don't ABSOLUTELY have to take this down for repair, don't mess with it. I wish I hadn't.
On to the trigger pull. The only way to lighten the trigger is to alter the striker spring. The design would indicate that resting length of the spring is crucial to reliable ignition, so coils must not be clipped from the spring. There is no commercially-available spring kit for this pistol, so I set about figuring what diameter spring stock would be best. The problem is that there is also a firing pin retracting spring, and the factory striker spring already has just the minimum force needed to overcome the retracting spring for reliable ignition. Scratch lightening the trigger pull.
I figured I would just have to smooth the pull out and be happy with that. The trigger pull on these guns stack horribly toward the end of pull (another spring function - gotta live with it) but are rough as cobs. Examination of the striker tunnel in the slide showed very rough machine marks as if it were never polished at all. Polished as much as I could without creating excessive play for the striker, and it still is rough as a cob.
So... almost six hours of bench work (with several interruptions) with a net result of.... zero. If anyone is thinking about getting one of these guns, do yourself a favor and buy something - anything - else.
