I want to thank all of you who have shared your trigger and tune-up tips.
Last weekend - acquired a CZ100, in .40 S&W. I hadn't studied up on it beforehand (mistake); but the price seemed reasonable, given the overall reputation of CZ products. Saturday and Sunday afternoons, I read everything I could about the model. It seemed that the preponderance of opinion was favorable.
By Tuesday afternoon, I was seriously concerned that the detractors were right!
The trigger was gritty; the magazines (it came with two for the price) wouldn't reliably seat when full, and wouldn't fall freely from the mag well unless empty. That wasn't enough, about every fifth shot, the slide would lock open even though there were still cartridges in the magazine. No jams, or stovepipes, just locked open - a pull on the slide would release it, and it was good for a few more shots.
After a few hours of diagnosing, I discovered two of the problems were related. The top round of the magazine was impinging upon the slide stop tab. The round was binding on the tab if a non-empty magazine was released, and the second round was partially lifting the tab as it rose to replace the round being stripped out of the lips.
I looked at the exploded diagram, and the tab appeared correct, but it was clearly interfering with two different profile bullets. First, I started with reshaping the tab to clear all the available bullet profiles, while endeavoring to leave the forward part of the tab as long as possible - to insure correct operation by an empty mag.
That done, I started on the trigger. I stuck with my "Arkansas" stone, rather than sand paper. The trigger bar cleaned up rather easily, but I think I will ultimately need to replace the trigger bar disconnector. The camming surface seems to have a groove in it, possibly worn in due to inadequate lubrication - this despite the appearance that it had hardly been fired, except that the inside was rather dry. Does
CZ ship these things with no or very light lube?
I lubed most everything with Dri-Slide, but used gun grease on the camming face of the trigger bar and disconnector. Result? The trigger isn't bad for a DAO, I guess, but still not as good as the factory job on my Rossi .44.
After the trigger job, I could observe a clear tendency of the barrel to twitch rightward right after the break. No it wasn't just me. I'd read about the "eraser" trigger stop, and started looking around for a suitable material. I ended up with a bit of tire tread from an old tire I hadn't yet junked. I would have liked for my trigger stop to be a Michelin, but I had to settle for a Dunlop.
In the end, I still don't know if most CZ100s required so much gunsmithing to make them reliable, but this one has a "B" serial number that is less than 100. I'm going to assume that it was just a lemon. I would certainly have hated to pay a professional gunsmith for all this work on top of the purchase price. I suppose that's why the guy sold it.
Oh, yes - and the magazine seating problem? I took about 1/64" off the bottom of the grip - end of problem.
Again, thank you,
Dale
