Problems w/ my CZ

[GTSteve03]

Howdy, I was hoping to get a little possible help/advice from the THR crowd regarding a problem I've been having with the CZ 75 Compact 9mm I bought recently.

At least once or twice every range trip, my pistol's slide will lock back open like the mag is empty, but there are still rounds in the magazine. I've not had any failures to eject, and the gun fires fine once I put the slide back into battery, but this is still a bit disconcerting.

I know I'm not hitting the slide stop with my hands during recoil, but other than that I'm not too knowledgable. The gun was used but appears to be in good shape. It has a full-length stainless guide rod, but I haven't replaced any springs yet.

Any ideas on why this might be happening?

 

[Squiggy]

Most likely the slide stop spring has bent over time which is allowing the slide stop to jostle around slightly during firing enough to catch the slide. The same thing happened to my CZ85b. All you need to do is remove the slide stop spring pin and pivot the slide stop spring up and then take it out. Take the slight bend out by bending it back to shape, and reassemble. Quite simple. That should fix the problem.

 

[Rumble]

Holy cow. I now wonder if the issue I've had with my P-01 is the slide stop engaging, and not a problem with the feed ramp. Come to think of it, I've always been able to repair the failures by pulling the slide back slightly and letting it slingshot, and in addition, I've never been able to see what part of the round was catching the ramp...

I need to work on my diagnostic skills, I think.

 

[GTSteve03]

Holy cow. I now wonder if the issue I've had with my P-01 is the slide stop engaging, and not a problem with the feed ramp.

Rumble, this is originally what I thought was causing my problem, either that or a weak mag spring. However, each time it happened recently I checked and the round in the mag had not moved forward at all, making me think the slide never unlocked.

My feed ramp wasn't mirror polished but I smoothed it out some with steel wool and it still happened, so you might want to check yours too and see if the rounds are actually leaving the mag.

Thanks for the tip re: the slide stop spring, Squiggy. I'm at work right now but I'll check it out tonight.

 

[Omega]

Does it happen with all of your magazines or just with particular one?

 

[CZguy]

Call Mike Eagleshield at CZ USA, and pick his brain. Phone: 1 800 955-4486

 

[GTSteve03]

Does it happen with all of your magazines or just with particular one?

I only have 2 mags, 1 is a 10-rounder, the other is a 13-rounder. I'm not sure if either is a factory mag* as I got the gun used. I seem to remember it happening more with the 10-rounder, but I didn't shoot that mag at the last range trip.

Call Mike Eagleshield at CZ USA, and pick his brain. Phone: 1 800 955-4486

Thanks CZguy, I'll give him a call if the slide stop spring doesn't fix the problem.

*I know, I am going to buy a couple of factory mags as soon as I can find them. The Compact mags are as rare as an honest politician, it seems.

 

[Riphalman]

It is quite possible that your slide stop is being brushed by the loaded rounds coming up from the magazine. An easy way to check would be to lock the slide back and slowly insert a loaded magazine into the well. Watch closely as the round comes up past the slide stop. If the round touches the slide stop.....there's your problem. A few strokes with a file to remove a bit from the slide stop will solve the problem. Remove only enough metal so that the tip of the round clears the slide stop. I had to do this myself and now my 75 runs perfectly.

 

[Walt Sherrill]

The most frequent cause for premature lockback is weak mag springs. Get some replacements. Wolff Springs.

(Someone suggested the slide stop might be getting hit by the nose of the rounds -- probably so, because when the springs are weak, that lets the topmost round slide around a bit during recoil, and it can be position to nudge the slide stop as the round goes forward.)

Try the mag springs first, then look at the slide stop spring. If you see "brass" on the slide stop that's a hint. (But unless it was doing this from day one, its not likely to be an out-of-spec slide stop.)