CZ75B Issues - AR15.COM

Posted: 6/5/2015 2:30:53 PM EDT

I picked up a used CZ75B and finally got a chance to shoot it today. About every other magazine I was having failures, if I remember right it wouldn't fully return into battery. I was using brand new Mec Gar magazines (16, 17 and 19 rounders) that I loaded a couple days ago, so I doubt it's magazine related. It was cleaned and lubed so I'm thinking the first thing to try is a new recoil spring, correct?

Posted: 6/5/2015 2:49:30 PM EDT

[#1]

Have you plunk tested the ammo and chamber? After that a recoil spring is a good place to start.

Posted: 6/5/2015 2:56:42 PM EDT

[#2]

What do you mean? I haven't heard of "plunk testing"

Posted: 6/5/2015 3:24:39 PM EDT

[#3]

It's more for checking head space issues but I've had some reloads that were too tight in some 9mm chambers and "plunked" in just fine in others. It's easy to just confirm that the ammo you have fits in the chamber easy.
Pull the barrel out and hold it with the open chamber facing up. Drop a live round into the open chamber and listen for it to plunk in. You should be able to spin it around with your fingers tips but the round shouldn't wobble any.

This video shows exactly what I was talking about: https://www.youtube.com/watch?v=s80P2j02YnM

Posted: 6/5/2015 4:02:23 PM EDT

[#4]

Quote History

Quoted:
It's more for checking head space issues but I've had some reloads that were too tight in some 9mm chambers and "plunked" in just fine in others. It's easy to just confirm that the ammo you have fits in the chamber easy.

Pull the barrel out and hold it with the open chamber facing up. Drop a live round into the open chamber and listen for it to plunk in. You should be able to spin it around with your fingers tips but the round shouldn't wobble any.

This video shows exactly what I was talking about: https://www.youtube.com/watch?v=s80P2j02YnM

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Gotcha, I've done that (with some sort of a sizing die) helping a friend reload 9mm before. I'll try dropping a round into the chamber of my G17, P226 and the CZ to compare

Posted: 6/5/2015 5:52:49 PM EDT

[#5]

Like this? If so its the recoil spring, zero issues since installing a 12 pound spring.

Posted: 6/5/2015 5:59:50 PM EDT

[#6]

Yes, almost exactly it. I'll try a recoil spring, thanks

ETA: swapped out recoil springs, the old one was about 1/3" shorter and felt a bit weaker. Hopefully a new one will do the trick. I'll hopefully take it out in two weeks and put a few mags through it to see if that fixed it.

Thanks again everyone

Posted: 6/15/2015 9:48:19 PM EDT

[#7]

Got a chance to shoot it today, I had 5 or 6 FTE's in 16 rounds (The point where I said screw it, something else is wrong)

Based on this thread (and the thread it links to) I probably need a new extractor spring (my extractor can be moved pretty easily by hand): https://www.ar15.com/archive/topic.html?b=5&f=37&t=91257

I'm guessing the extra power spring is the way to go? Anything else I should swap out at the same time?

Posted: 6/15/2015 11:44:18 PM EDT

[#8]

cgw doesn't seem to be really into the extra power springs. Have you tried to clean the extractor? I'd try removing the pin and the extractor and spring and see if anything's there. I had a ftf problem that I thought for sure was an old recoil spring, but when I had it apart I took the extractor out of the slide only to find carbon had built up that the extractor didn't have a full range of motion.

Posted: 6/16/2015 3:00:41 PM EDT

[#9]

I'll give that a shot and try the spare extractor spring I have (not extra power) and see if that helps...

Posted: 6/17/2015 8:23:57 PM EDT

[#10]

I get FTEs on my TS when its extractor gets too dirty. Definitely worth pulling and cleaning it, and if you've got a fresh spring, throw it in there too.

What ammo are you using? (If handloads/reloads, what are the specs?)

Posted: 6/17/2015 8:25:59 PM EDT

[#11]

It looks a bit dirty so hopefully that'll do it. I was shooting CCI Blazer Brass, WWB and Magtech 115gr... Doubt it's the ammo

Posted: 6/17/2015 8:32:36 PM EDT

[#12]

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Quoted:
It looks a bit dirty so hopefully that'll do it. I was shooting CCI Blazer Brass, WWB and Magtech 115gr... Doubt it's the ammo

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FWIW, WWB is actually pretty shitty in 9mm. It often has out-of-spec extractor grooves. The handful of FTEs I've had in a decade of shooting 9mm CZs have ALL been with WWB brass.

Blazer Brass is definitely GTG, and Magtech should be fine.

Posted: 6/20/2015 9:44:46 PM EDT

[#13]

Would a good polishing of the ramp and chamber do anything here?

Posted: 6/20/2015 10:02:25 PM EDT

[#14]

Since I'm now having ejection issues I doubt it

Posted: 6/21/2015 1:36:40 PM EDT

[#15]

Quote History

Quoted:

FWIW, WWB is actually pretty shitty in 9mm. It often has out-of-spec extractor grooves. The handful of FTEs I've had in a decade of shooting 9mm CZs have ALL been with WWB brass.

Blazer Brass is definitely GTG, and Magtech should be fine.

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Quote History

Quoted:

Quoted:
It looks a bit dirty so hopefully that'll do it. I was shooting CCI Blazer Brass, WWB and Magtech 115gr... Doubt it's the ammo

FWIW, WWB is actually pretty shitty in 9mm. It often has out-of-spec extractor grooves. The handful of FTEs I've had in a decade of shooting 9mm CZs have ALL been with WWB brass.

Blazer Brass is definitely GTG, and Magtech should be fine.

I reload and have seen those extractor groove dimentions and out of spec rims on Winchester 45, 9mm, 38 special and 32 acp. The 45 was thin brass walls larger internal capacity. The 9mm the extractor groove. 38 Special has a funky rim thickness and primers end up high when the press sets all other brands just right. 32 acp was just thin brass compared to every one else. Now I have some Winchester nato 9mm military cases that are nice soft brass with great extractor grooves.