Quoted:
I called Para customer service. I said I tried a number of high quality sear springs and none would work properly in their gun. I asked if there was a problem with the slot location on this gun and they only said that "we make their own spring..."
Considering I have tried every well know 1911 sear spring available, I believe they had a manufacturing problem. All other parts and even other hi-cap triggers and mags from other brands work fine in my Para.
It's true, they do use a non-standard proprietary sear leaf spring of their own design, unfortunately.
I ordered mine from Brownells and now have two spares. It's a cheap part just order it from Brownells and tune it to your specifications/needs.
Like you, I also had tried a few traditional sear leaf springs from different manufacturers and they plain just don't work on Para 1911's. The dimensions of the sear leaf is different and the para spring has a slight bend or crook in that leaf that you just can't duplicate with a traditional/standard 1911 leaf spring. Compare two side-by-side and you'll see the difference.
Don't even ask why I was replacing the leaf spring, this gun was bought new and was a nightmare right out of the box in several ways. I even sent it back to PO to get some things fixed. At least it fed properly with the original PO mags once I received it back from PO. But they didn't fix anything else wrong with it.
So I made it my project gun and did the rest of the work myself. I'd worked on 1911's before and had the knowledge and time to do the work myself.
Lowered and squared the frame rails, squeezed the slide and those two actions improved the slide/frame fit, performed a trigger job (good crisp 5-lbs, just right for carry), fixed the disconnector slot depth to fix the disconnector click at the end of the trigger pull just before sear releases hammer, fixed the uneven wear on slide dustcover, even refnished the crappy peeling "Stealth" finish which you could scrape off with a fingernail by blasting and Cerakoting it myself.
The gun is now 100% reliable and accurate with both original PO 14-rnd mags, and all 10 of my Mec-Gar 14-rnd mags. Never got the 20 Promag 14-rnd mags to work reliably, but they work at almost 95% now. I use them on occasion for training to clear feed jams and clearing. They are erratic and sometimes will work for several hundred rounds then out of the blue a feed jam. The PO and Mec-Gar mags are 100% reliable now after thousands of rounds.
In any case this PO WILL be the only and LAST PO product I'll ever buy. Their customer service and repairs just plain suck, even after George Wedge taking over and their move to the USA you can go to both well known 1911 sites on the web and still hear horror stories of their service to this day. The hope was with George taking the reigns of the company and taking over support all that would change and the QC for new guns would improve, it hasn't.
Too bad too, cause George is a stand up good guy. If Mr. Szabo were alive today, he'd be highly disappointed in what has happened to the company he founded. :>(