New CZ 97B jamming

M

Moloch

New member
Hey guys!

I just got me a brand new CZ 97B in .45 ACP, I shot 60 rounds factory 230 grain ball FMJ through it and every 15-20 shots it would jam an unfired cartridge between the barrel and slide, with the projectile pointing up. Its mostly the 5th or 8th round of the magazine. :(

Any ideas what the problem could be? I'm definitely NOT limp-wristing it, I'm holding it correctly, it does this with both magazines that came with the gun. I inspected and cleaned & lubed the gun, everything looks good. It ejects the brass correctly, the feed ramp has a mirror polish and its a 2018 model with the long feed ramp. Ejector pressure also seems fine.

Dry cycling it with dummy 230 grain Ball rounds it works just fine, no resistance or hiccups.

Its a factory new gun, do I simply need to break it in? So far I only got 60 rounds through it. :confused:

It does that with FMJ ball ammo and also my 200 grain handloaded truncated cone projectiles loads. During feeding it also bumped one projectile deep into the case, that's when I stopped shooting my hand loads.

4OxDT4z.jpg


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That's disappointing, certainly. I can't tell you the problem, but I can assure you that you're in good hands with CZ service.

I suggest that you get in touch with them. They are very responsive and prompt.
 
It is a magazine issue, most likely. The feed lips let go of the fresh cartridge prematurely. Try closing the lips slightly. If you don't know how to adjust it, either send it back to the manufacturer or take it to a gunsmith. Try another magazine if you have one.

-TL

Sent from my SM-N960U using Tapatalk
 
The thing is, if I cycle it extremely slowly with dummy rounds and I watch and feel the process of the slide stripping the round and chambering it, it all looks very good and works buttery-smooth. I cannot imagine what could go so wrong when shooting it.

I had a rifle (Swiss K11 straight pull rifle) that had a bad magazine, the round fed from the right side of the magazine would always result in a similar problem, it would rise way too high during feeding and getting jammed between the bolt and the chamber. The problem was exaggerated when working the bolt very slowly.
I bent the right magazine lip inwards so the round would fed from a less steep angle and also guide the round longer - and it worked perfectly ever since.
 
Did you give it a thorough cleating to remove the packing grease? My friend just bought a S&W M&P. There was no visible grease, but the first 2 rounds had light primer striikes. A liberal spray with WD-40 solved the problem. We presume there was grease in the firing pin area slowing it's travel.
 
It's hard to tell from the pictures but it looks like it's bone dry. Being a new gun run it wet until it breaks in.That may take care of your problem.
 
Brought it back to the store where I bought it, we tried different brands of ammunition and weirdly enough, we shot 50 rounds of Fiocchi 230 grain ball with zero malfunctions.

One thing I know about Fiocchi is that they load their stuff pretty hot, so maybe its a recoil spring issue?
 
Yours wouldn’t be the first CZ manufactured with a tight barrel throat that needed a couple hundred rounds through it to loosen things up a bit. I once had a CZ 75B in .40S&W that had a similar problem but I didn’t keep it long enough to diagnose & fix the problem.
 
Mag spring, or recoil spring.

Mine didn’t play nice with lswc’s. Removed the loaded chamber indicator and it fixed the problem.

Those stove pipes you have pictured are pretty gnarly though.
 
Dan-O said:
Mag spring, or recoil spring.

Mine didn’t play nice with lswc’s. Removed the loaded chamber indicator and it fixed the problem.

Those stove pipes you have pictured are pretty gnarly though.
Click to expand...
I actually wondered, does the loaded chamber indicator even need a spring? I mean it offers resistance to the round sliding all the way under the extractor, but it would work just fine without the spring I think.
 
Dan-O said:
The lci is worthless to me. All guns should be treated as if they’re loaded. Always.
Click to expand...

Well, I think it serves a purpose, you don't have to do a press check, just look at the indicator for reassurance.
 
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Dan-O said:
The lci is worthless to me. All guns should be treated as if they’re loaded. Always.
Click to expand...


I actually find that rule poorly written in context with the others. What does that mean exactly, when you think about it, to treat a firearm as if it’s loaded? We already know we don’t point the pistol at people or objects we’re not willing to destroy. We also know not to have our fingers on the trigger unless we’re “ready to fire”, so to speak. So what does “Treat all firearms as if they’re loaded”, actually add to safety awareness? Moreso, not all firearms are loaded. That’s factual. If it’s a firearm we plan to use for self defense, it would be nice to know if it is in fact loaded. Loaded chamber indicators are one way of doing that.


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Appears to be magazine related, so I would load the magazines with five round only to start and shoot a few to see if that makes any difference, then load 7 rounds and so forth. You stated that it is generally around the 5th or 8th round so by varying the amount of rounds you load in the magazine, you might be able to pin it down what the problem is.
 
I think I fixed it, I found reddish rub marks on the inside of the slide hold open lever, apparently during the feeding process the projectiles came in contact with it. I removed some material until the very aggressive edge was gone, and polished the heck out of it.

I also polished the feed ramp to a mirror bright finish.

Now I did 85 shots with 3 different brands and my handloads. Zero malfunction!

Here is the slide stop lever before I polished and disarmed the edge:

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@moloch, what part of the slide stop did you polish? That is a rather rough looking piece for a CZ. Disappointing.
 
The tab the follower of the magazine pushes up to engage the slide lock is what I polished. In the picture you can see the tab has reddish rub marks from the projectiles and two rather sharp edges. I turned that entire surface into a homogeneous round and polished shape, slightly smaller in size so the projectiles would not rub against it.
Still more than enough material is left to ensure reliable slide hold open on the last round.-

Thats how it looks now:

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