CZ-52 Question [Archive]

gunnut1

November 09, 2003, 21:27

Clark strikes again.

He has been spreading this all over the other gun boards. It is beyond me why someone would purposely overload a gun just to see if it will blow up. ANY gun will blow up if you purposly overload it! If you use the ammo designed for the CZ52 pistol, you will not have any problems. There have been some reports of some problems with some Bulgarian sub gun ammo but that is all I have heard of.

Remember, ANY military surplus or used gun you obtain should be check by a comptent gunsmith before you shoot it.

Get the CZ52. Consider this. If the CZ52 is such a piece of junk and blows up all of the time, then why don't we hear about it? The roller lock action is probably the strongest locking action built.

I have a CZ52 and I love the gun. And I would not have a problem carrying it for a conceal carry gun.

Clark, can you provide documentation to prove what you are saying? It seems you have a presonal bias against the CZ52. I have seen your dribble on other gun boards. Prove what you are spouting!

More on the CZ 52 (http://www.falfiles.com/forums/showthread.php?s=&threadid=67826)

Clark

November 09, 2003, 22:16

I have been overloading rifles, shotguns, revolvers, and semi auto pistols for 5 years.

I am an electrical engineer specializing in designing switching power supplies, and I think I have maintained reasonable documentation on my firearm overload experimentation.

There is nothing special about my findings except the CZ52.
It is not like any other guns of it's type.
It is weak.
I feel compelled to tell as many people as possible.

My father is a successful gun designer and he thought I was nuts blowing up guns, until I showed him my documentation. That seems to make it ok with him.

That will not mean much to CZ52 owners that take my data as a personal affront.

Gunnut says, "ANY gun will blow up if you purposly overload it!" That is not true about incremental increasing powder charges until the brass or the gun fails. Of the 21 semi auto pistols I have overloaded until the brass or the gun fails, only the CZ52 had the gun fail.

25acp:
Colt is stronger than the brass
Vesta is stronger than the brass
32acp:
Kel-Tec is stronger than the brass
.380:
Berretta is stronger than the brass
Husqvarna is stronger than the brass
9mm
Star [M43] is stronger than the brass\
Glock 19 is stronger than the brass
Kel- Tec is stronger than the brass
Star Super B is stronger than the brass
Tokarev is stronger than the brass
7.62x25mm:
CZ52 is weaker than the brass
Tokarev is stronger than the brass
C96 is stronger than the brass
9x23mm:
Tokarev is stronger than the brass
Star Super B is stronger than the brass
40 S&W
Kel-Tec is stronger than the brass
Glock 22 is stronger than the brass
10mm
Glock 20 is stronger than the brass
45acp:
Patriot [Cobra] is stronger than the brass
Colt 1911 is stronger than the brass
Para Ord P10 is stronger than the brass

Why is the CZ52 the only pistol weaker than the brass?
Because it is the only pistol with a chamber that thin.
It is thinner than the others, even when hoop stress is calculated for larger chamber diameters.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

stv

November 09, 2003, 22:26

I've had my CZ for only a short time but have shot at least 100+ rounds out of it and it has'nt blown up yet.. ;)

valc67

November 09, 2003, 22:30

I recieved a CZ50 last week and was so impressed I'm going to order a pair of CZ52's tomorrow [can't beat that 100.00 price tag]. If the surplus ammo is too hot, I'll just rebarrel to a 9M. I've heard nothing but praise on the 52, except for the firing pin. There seems to also be plenty of spare parts on the market.
Fill that 50 year old Chevy with aviation fuel and see what happens.

Clark

November 09, 2003, 22:55

I don't think the 50 year old Chevy analogy is valid.
The age is not the issue, chamber wall thickness is.
Guns that are 100 years old and have a thick chamber wall are much stronger than the 50 year old CZ52 with an unusually thin wall on the bottom.

The roller blocks fit in a recess in the bottom of the barrel that is milled out. It is milled .240" deep. Chamber to the bottom of the barrel is .300" . The difference is the thickness for strength calculation. The bottom of the chamber of the CZ52 is only .060" thick. That is the whole length, and thinner where the retainer pin hole is drilled.

There are no other other semi auto with such a thin chamber. Even the 25 acp pistols have a thicker chamber wall.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

FWRA

November 10, 2003, 00:02

Well I see the CZ52 troll is back. :biggrin:

You guys listen to Clark.......he's an electrical engineer with a whole bunch of experience in the ultimate quest for adventure....working up max loads in guns in an attempt to blow 'em up.

Better e-mail me and I'll buy all these dangerous CZ52's from you before you hurt yourselves.

Good grief..... :sad:

FWRA

7idl

November 10, 2003, 01:10

why should we be worried about OVERLOADED ammo? who here (besides mr clark) is going to do that?

I feel it would be safe to say that everyone here (~) would most likely be using surplus or newly mfg ammo.

and in regards to the bulgarian crap, here is a link:

http://www.geocities.com/Yosemite/Gorge/4653/bad.htm

I too like my CZ-52

Like any other firearm, respect it and take care of it! overloading it is not taking care of it!

gunnut1

November 10, 2003, 05:59

So Clark,
Since when does being an eleCtrical engineer make you qualified to be a weapons expert on the metallurgy of guns. I don't think they teach that in the engineering college.

Clark,

AGAIN I SAY, SHOW US YOUR DOCUMENTATION ON THE BRASS, BULLET AND THE AMOUNT AND TYPE OF POWDER YOU USED TO BLOW THIS GUN UP.

I am not in the least worried about my gun blowing up in my hands if I use the proper ammo in the gun.

Now there was that thing about the WAC receivers!

pmf

November 10, 2003, 08:07

Everyone should get a CZ-52. They're cheap, operate on rollers, shoot a funky round that probably penetrates body armor, and there is a huge muzzle flash. Plus, they're C&R eligible. If you don't have a C&R -- get one. Its the best $30 you'll ever spend.

Personally, I think the Mosin Nagant I got last month for $80 is much more fun than a CZ-52.

Realize though that they are what they are -- a cheap, old fashioned handgun. The ergonomics aren't great, the trigger sucks and the sights are poor. The firing pin will break if you dry fire it. Some people claim they are very accurate, but that's not been my experience.

There are a ton of upgrades for them. The firing pin/trigger enhancement sold by makarov.com for $45 is well worth the money. It vastly improves the trigger and gets rid of the firing pin breakage problem. After market grips are an improvement worth considering too. You can spend hundreds of dollars on upgrades it you want.

As far as ammo goes -- I don't trust the surplus stuff that's going around. I had some that was really poor -- 50% didn't fire and I got one hang fire. Get the S&B new production ammo. You can get it at decent prices.

All is all, a makarov will probably work better out of the box, but a CZ-52 truly is a unique beast.

Clark

November 10, 2003, 10:31

FWRA,
If I am a troll, then I could ask, Why did that moderator write to you, "And I thought you were a guy."?
Are you not a guy?
"My friends think I'm ugly, I gotta masculine face." -Tom Waits

Gunnut, you ask for proof, and I post results.
Now you impeach my credentials.
I have the same EE degree from the Univ. of Wash that my father does, and he designed the M107, M110, and M158. I am not the qualified gun designer he is, but he is giving me lessons in calculating gun strength.

But that would make no difference to someone only interested in justifying their CZ52.

I own 5 or 6 CZ52s, and for strength, they are the worst guns I own.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Mad Dog 7.62

November 10, 2003, 14:56

I have just read this entire thread twice, and I am still sitting here scraching my head. :confused: :confused: I am somewhat baffled by Clarks statements about the "brass being stronger than the gun". I presume that if he is experiencing a case failure with his "overloads" prior to acheiving a catastrophic failure of the firearm he is presuming that the gun is stronger than the brass. However, it would be rather impossible for the barrel to rupture and the brass to be intact. So how does he reach the conclustion the brass is stronger than the gun? He is stating that the Cz52 has a chamber as thin as .060....how thick is the brass he is using? That would have to be pretty tough brass to be stronger than a .060 steel chamber. :eek: I think his testing methods and understandings of even basic firearms design might leave something to be desired. Just because a case ruptures without the firearm having a KB, doesn't mean the firearm is strong. Just because you can cause a firearm to KB by using a unspecified "overload" in it doesn't mean the firearm is "weak". The case and the chamber serve two different functions, to compare the strength of one to the other is like comparing the front tire of a car to the engine. Maybe entertaining for a caveman, kinda boring to the rest of us.
MD

gunnut1

November 10, 2003, 16:38

Originally posted by Clark

Gunnut, you ask for proof, and I post results.
Now you impeach my credentials.
I have the same EE degree from the Univ. of Wash that my father does, and he designed the M107, M110, and M158. I am not the qualified gun designer he is, but he is giving me lessons in calculating gun strength.

But that would make no difference to someone only interested in justifying their CZ52.

In a society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

I have impeached your credentials? How do you figure? All I am saying is that elecrtical engineers are not metallurist. It is obvious to me that your dad has had some training in metallurgy. THAT'S GREAT! I have no doubt that you are damn good at what you do! I am sure you dad is more than qualified to do what he does. Your qualifications are not in question here. Your methods are. I am an industrial electronics technician. But that doesn't make me a weapons expert and I damn sure don't know that much about metallurgy! I still contend that if you over load ANY gun enough, it will blow up.

I guess my knowledge of guns is not a broad as I thought. What is a M107, M110, and a M158? Sound military to me.

Yes, I asked for proof. Proof of pressures generated when you overload the cartridge. How many PSI did the overloaded cartridge generate and how much is the CZ52 rated for? What is the standard proof load for the CZ52? All I have seen is a picture of a blown up barrel. I REALLY don't think that is proof.

Clark look, I REALLY don't want this to turn into a pissing match. I understand what you are trying to do. But the problem is, as stated above, the methodology about which you are approching it. Have you considered having a certified lab do the testing? If you are that concerned about the safety of the gun, then it would be better accepted if you could provide documentation from a certified testing lab. If the CZ52 is a bad as you say, I will be the first one to throw mine in the garbage!

In another thread, you state that the CZ52 "slipped through" the saftey test when it was imported. Can you elaborate on this? I didn't think there was a saftey test that guns had to pass before they are imported? But I have been wrong before. I would be VERY interested in what this involves.

Clark

November 10, 2003, 22:16

Mad Dog 7.62,
When I say the brass is stronger than the gun, what I mean is that the brass case will seal the pressure up to a pressure where the chamber ruptures.

This test the CZ52 is unique in failing.

FWRA

November 10, 2003, 23:57

Clark-----

FWRA,
If I am a troll, then I could ask, Why did that moderator write to you, "And I thought you were a guy."?
Are you not a guy?

????

Wow....that was left of center. You must have me confused with someone else.

The troll comment was kinda tongue in cheek, but it amazes me that you have to post your CZ52 destruction findings on every CZ52 post that crops up.

My father is a successful gun designer and he thought I was nuts blowing up guns, until I showed him my documentation. That seems to make it ok with him.

Seems to be OK with him? I don't have a son (two daughters) but if I did and he came to me explaining he was blowing up guns I think I'd try to steer him to a different hobby. :)

If these military pistols were as dangerous as you imply we'd be awash in CZ52 KABOOM postings.

Give it a rest. We've all heard your story dozens of times.

FWRA

Clark

November 11, 2003, 00:19

Thanks for taking down the misleading picture.

You have your job selling CZ52 stuff, and I have my job, experimenting.
Too bad if the data doesn't fit your business plan.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

stv

November 11, 2003, 09:55

Clark
Your job is an official gun tester? I did'nt know that...

I can see how being an electrical engineer would make you an expert....:rolleyes:

I'm a Hoisting engineer that works foer a plumbing Co.

Am I an expert too? ;)

Clark

November 11, 2003, 12:33

The task of designing a switching power supply and the task of designing a gun both involve math. Take away the units, and you would have a hard time discerning the difference between the two.

The hoop stress that causes the CZ52 to fail prematurely mathematically looks allot like calculating rms currents in a transistor. It is just jr. high math.

I am not designing a gun.
I am simply doing some failure analysis on a CZ52 and ran into a design error.
As I have done thousands of times in other things.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Queenie

November 11, 2003, 13:12

How can it be a design error if you are subjecting the gun to forces far in excess of the design parameters? The pertinent question, which you seem unwilling to answer, is HOW FAR over design parameters are you subjecting the weapon? All you may have discovered is the CZ 52 may not have as much a "margin for error" as other pistols. Not that they are inherently dangerous if used as designed. IF there was a problem with CZ 52's and catastrophic failures from normal use, then I'm fairly certain it would have been "discovered" by now.

Queenie

November 11, 2003, 14:05

Lets take this whole thing a little farther. What PRACTICAL knowledge can we gain from Clark's "testing"? Uhh...don't load up a casefull of Bullseye in a CZ 52, it will blow up? No shit...Sherlock. :rolleyes: Until you post some data, you cannot expect anyone to look at your results with any credibility.

Clark

November 11, 2003, 14:26

What can you learn?
Many people think that Bullseye is the way to blow up guns because it is fast.

When one tries to blow up guns, one will find that often, like with 25 acp, 32acp, 380, and 9mm, not enough Bullseye will fit in the case with a bullet to get the pressure up.
AA#5, 3N37, and HS-6 have a higher speed - density product and can make trouble when Bullseye can not.

Of course, with a 30-06 and a 180 gr. bullet, there will probably be enough space to make trouble with Bullseye.

*the CZ52 has 9mm barrels available and is too weak to try this experiment.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Batman

November 11, 2003, 20:23

I'm confussed!:(

Fred

November 11, 2003, 20:45

Clark,

It would seem that the fundimental question that has been asked as often as you post is what are you using as destructive loads. You will not have any creditability until you do lay the test conditions out so that someone else can verify your claims. The burden is upon you to present your case in a complete and factual manner. Unsupported wild claims of the 'sky is falling' only hurt you, even if you may be right!

Just so my cards are on the table, I am also an Electrical Engineer, with a number of patents and many years of plying my trade. My credentials do not make me a mechanical failure expert, even though I am a fair gunsmith. One thing that is learned early in engineering is that to make a claim or challange it must be backed with facts. A failure photo can only be a supporting piece of data. So it would seem that you will either need to put up or shut up. The choice is yours to make.

Fred

masman

November 11, 2003, 20:50

ok i have one for you clark.if the cz-52 is so weak, why do some ammunition manufactures and reloading manuals say thier loads are ok for the cz-52 but not for the tokerev?

Clark

November 11, 2003, 20:58

Fred,
I sent all my 7.62x25mm load notes to you in a private meassage.

masman,
Because they have not read and accepted my posts.

Calvert1

November 11, 2003, 21:06

The more logical reason is that they probably know more than you. An ammo company isn't likely to make claims that leave them open to litigation without some pretty thorough testing.

How many pistols have you "tested"? Enough to constitute a representative sampling? Pardon me if I trust a respected ammunition manufacturer more than an engineer with too much powder and a pair of calipers.

masman

November 11, 2003, 21:12

thats not really the answer i was looking for.what made them think the cz-52 was stronger?they must have done some testing.in this age of getting sued for spilling hot coffee on yourself.i would think they would want to cover thier asses for liabilty reasons.one last question for you. in your opinion do you think the cz-52 is safe to use with "factory "ammo?

Clark

November 11, 2003, 21:27

I wrote to Sierra about the line in their book about the CZ52 being stronger than the Tokarev.
I showed them my data.
They confessed that they had no data on CZ52 strength, and were just printing what they read.
I offered to send them a number of CZ52s for destructive test, and they declined.

I believe the head waters of the erroneous information about CZ52s may have started from:

the U. S. Army Foreign Science and Technology Center's publication titled "Small Arms Identification and Operation Guide - Eurasian Communist Countries", (FSTC-CW-07-03-70), page 211, Table XI, Cartridge Data and Color Codes, in reference to 7.62 x 25 mm pistol ball type P;

"Do not use Czechoslovak-made ammunition in TT-33 pistols."

quote:Johnson H.E. Small Arms Identification and Operation Guide - Eurasian Communist Countries. US Army Foreign Science and Technology Center, Army Materiel Command. US Govt. 1970. [19489.]

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Mad Dog 7.62

November 11, 2003, 23:15

Originally posted by Calvert1
Pardon me if I trust a respected ammunition manufacturer more than an engineer with too much powder and a pair of calipers.

ROFLMA!!:biggrin: :biggrin: :biggrin: :bow:

Queenie

November 11, 2003, 23:47

OK....I've learned that you can't get enough Bullseye in smaller pistol cases to blow them up. Thats cool if I want to blow one up. Clark...The type of powder is really irrelevant. Bullseye is most often associated with overload problems because standard loads are relatively small and its easier to load a double charge without noticing it. Thats why it has a reputation for causing problems. The point is unless you can show the pressure levels it takes to blow up a CZ 52 and how these pressures relate to existing loadings or maximum published load data, you are wasting your time. In effect you are doing no more a "service" to CZ 52 owners than the standard "Warning" not to exceed published data found in any reloading manual. If you can show these failures can occur from pressures generated by accepted published load data or from common loaded ammunition (the issue with the Bulgarian is noted) then you are getting somewhere. You still are not answering the right questions.

FWRA

November 11, 2003, 23:55

Quality Cartridge Company ad taken from their website:

.223 Timbs

!!!!!!THESE LOADS ARE INTENDED ONLY FOR THE CZ-52 PISTOL!!!!!!

The .223 Timbs is the result of a co-development between Quality Cartridge and Joseph Timbs. It is the American answer to the proprietary .224 BOZ, bringing the CZ-52 into the new millenium. The .223 Timbs is a special loading of the 7.62x25 round for use only in the CZ-52 pistol. It consists of a sabot like the Remington "Accelerator" pushing a 50gr bullet over 2000fps. Concept was for devastating multi-purpose round, useable for small game, varmits, and defense. Accuracy has proven to be on-par with traditional rounds fired from the same pistol, and terminal ballistics are quite impressive with initial tests showing devastating expansion from the varmit-type bullets.

Use EDIT/COPY and EDIT/PASTE to place desired items on Order Form

Prices Shown are for Retail Customers, Dealers Please Call for your price OR use Dealer Price Sheet.

Sabot ("Accelerator"*-Type) Loads

Bullet Wt. Price (Bx 50)
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Please note:
Peter Cardonna of Quality Cartridge has EXTENSIVE experience with the CZ52 pistol and has many hot loads designed for this pistol only. Each box has a big green label..."FOR CZ52 PISTOL USE ONLY!"

He must know this pistol is a weak and dangerous design.....yes? :D

Here's an e-mail from Peter telling me about some of his hi-vel CZ52 ammo. (I've shot it all in both lock stock and custom CZ52's)

----- Original Message -----
From: "peter cardona" <abn82d@hotmail.com>
To: <mpowell5@neo.rr.com>
Sent: Tuesday, April 30, 2002 10:51 PM
Subject: 7.62x25

> Mark,
>
> 7.62x25 CZ52 ammo ONLY fOR CZ52!
>
> 60gr XTP $26.97 1900fps
> 71gr FMJ $17.97 1900fps
> 85gr RN $20.97 1800fps
> 90gr JHP $23.97 1700fps
> 90gr XTP $26.97 1700fps
> 100gr XTP $26.97 1650fps
> 110gr FMJ $23.97 1600fps
> 110gr JHP $26.97 1600fps
>
> CZ52 Sabot loads are ~2000fps+
>
>
>
> If you have any other questions, we will be more than happy to help.
>
> Thank you,
>
> Pete at Quality Cartridge
> SC

Now I believe if Clark would call Peter and warn him about his destructive CZ52 testing and warn Peter of the inherant danger he faces, Peter would, what, say "Gee thanks for that info. I was going off information that the Army published......."

Nope. He'd probably listen to him for a few minutes and say Thanks for the heads up but I've got backorders for ammo to fill. Gotta run....Bye!"

FWRA

Clark

November 12, 2003, 02:11

I don't have to show pressure levels. There is no SAAMI standard for the Tokarev round.
All I have to do is show that the books are wrong: The CZ52 is not stronger than the Tokarev and I have proved it.
I have also shown that the CZ52 does not have the sort of safety margin that 21 other semi autos up to 100 years old all show.
If the question is, "Is the CZ52 a good pistol?", it must be answered with the qualification that, books on the subject are in error and the safety margin is actually poor.
I may be the only one saying this, and there are lots of other voices saying otherwise, but to quote Fritz Perl, "It doesn't matter how many dogs bark up the wrong tree, it is still the wrong tree."

You ask anyone who says or implies that the CZ52 is stronger than the Tokarev where he got his information. I have. There is nothing out there but a house of cards.

That guy with the Timbs has no information on the CZ52 being stronger than the Tokarev. He is just making assumptions based on the crap that is written.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

masman

November 12, 2003, 05:08

Originally posted by Queenie
OK....I've learned that you can't get enough Bullseye in smaller pistol cases to blow them up. Thats cool if I want to blow one up. Clark...The type of powder is really irrelevant. Bullseye is most often associated with overload problems because standard loads are relatively small and its easier to load a double charge without noticing it. Thats why it has a reputation for causing problems. The point is unless you can show the pressure levels it takes to blow up a CZ 52 and how these pressures relate to existing loadings or maximum published load data, you are wasting your time. In effect you are doing no more a "service" to CZ 52 owners than the standard "Warning" not to exceed published data found in any reloading manual. If you can show these failures can occur from pressures generated by accepted published load data or from common loaded ammunition (the issue with the Bulgarian is noted) then you are getting somewhere. You still are not answering the right questions.

:bow: :bow: :bow:

Poccur

November 12, 2003, 11:53

The task of designing a switching power supply and the task of designing a gun both involve math. Take away the units, and you would have a hard time discerning the difference between the two.

Great, you design switch mode units...A noble profession.
If a customer phones your tech line and says 'I am applying 460 volts to the 120 volt input of my power supply and it fails. I think I have discovered an inherent weakness in the design'

What are they gonna be told?

'The 12 volt output line will only give me 12 volts at 1 amp, it is not upto starting my car...This design is weak.'

Do you think they will get listened to?

You have discovered that if you overload a round the pistol will fail...congratulations. You have proven that the limits are there for a reason..Brilliant. This is useful stuff to anyone who was wondering why these limits exist. For the rest of the world its not really relevant.

If you work from the statement ' I overloaded the round and the pistol exploded therefore the CZ is weak'
Now apply Ockham's razor...
You overloaded the round..proved
the pistol ruptured...proved
therefore the design is weak....supposition on your behalf.

If you accept the first two statements you have facts....The moment you assume that the third is true because of the first two you have departed fact and then have to assume that if this is correct, CZ52s are failing all over the country because it is a widespread frequently used pistol.
The razor would be applied and the first two statements count and the third has to be discarded.

Initially I thought you were just 'anti' the CZ52 but then I discovered 'Hanlon's Razor' and I am happier with the answer that gives us.

Poccur:)

American Revenge

November 12, 2003, 12:00

Proof flavored pudding,

Has anyone else had a Cz-52 catastrophic failure?

I am conducting similar experiments using a large ring mauser loaded through the muzzle with 150 grains of Accurate 3100 and a plugged barrel, I've gone through ten rifles and all have failed. This clearly represents a design flaw. Paul Mauser was clearly in error.:biggrin: :biggrin:

Just funnin Clark, enjoy yourself! (please wear safety glasses)

fastfreddy

November 12, 2003, 12:25

I think the experiment is interesting. I assume that it involved a statistically meaningful number of CZ-52s. It seems that rather than all the blustering and nay-saying maybe somebody should replicate the experiment and see if the results can be independently reproduced. I doubt that will happen because why would somebody be motivated to check this. Certainly those who sell or own CZ-52s wouldn't want to blow 'em up. Everybody else doesn't care enough to spend the money.

I do not think that the CZ-52 is an unsafe gun but I do think the results of the experiment present interesting information.

I also do not consider the Spanish 1916 mauser chambered for 7.62 X 51 to be unsafe. It seems unusual to me that the consensus of this board is that the 1916 is NOT safe, despite experimental data that it is, and that the CZ-52 IS safe even when confronted with possible contrary experimental data.

Maybe FALfilers just don't like experimental data.

As for Clark, I think he has enjoyed his experiments and is excited to have actually possibly learned something. He just wants to be validated. If it weren't for the CZ-52 results, his experiments would have been a big yawn.

Clark

November 12, 2003, 13:24

I overload power supplies all the time, but seldom with Voltage.
Mostly it is with out put power and ambient temperature
They explode like firecrackers.
I have to figure out why they blew up at that level and improve them so they blow up a higher level.

Mauser 98s are the best design I have seen and a stark contrast with the CZ52, which is one of the worst.

Here is a picture of three rounds I fired in a 1938 Turkish Mauser [98 design] The loads were 40 gr. IMR4895, 100 gr., in .308 LC brass necked down, but not reamed. This picture has been downloaded about six or seven thousand times.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

http://www.thehighroad.org/attachment.php?s=&postid=49766

Queenie

November 12, 2003, 14:04

Here is a picture of three rounds I fired in a 1938 Turkish Mauser [98 design] The loads were 40 gr. IMR4895, 100 gr., in .308 LC brass necked down, but not reamed. This picture has been downloaded about six or seven thousand times.

A 38 Turk. In 8x57mm? I assume you mean 30.06 LC brass? Regardless...why would you neck down .308 brass to load in an 8mm? Your data is confusing. 40gr. IMR4895 is not an overload. 100 gr.???? What?

Anyway back to the CZ....You DO need pressure data if your findings are going to have any merit in the REAL world. Your conclusion about the CZ vs. other pistols is flawed because you MUST change the parameters to load the various sized and shaped cases. One obviously cannot load the same amount of the favored powder into a .25, .32, .380 case as in a 7.62 Tok. Saying a Colt .25 ACP is stronger than a CZ 52 using your method is not accurate unless you can show both pistols were subjected to the same stresses. Your experiment does however have merit in regards to the Tokarev and the CZ as you can closely duplicate the test from one to the other. However, have you considered that the CZ's reputation for handling hotter loads than the Tokarev might be based on other things beside chamber strength? How does the design of the CZ affect factors involving stresses to the pistol other than its ability to hold together under extreme overloads? How about a 10,000 round torture test? Considering your line of work, I can't understand how you can leap to such conclusions.

Clark

November 12, 2003, 14:20

Sorry, I rebarrelled that Turk to .243.

My contention is that the Sierra load book is wrong when they said that the CZ52 is stronger than the Tokarev.

To prove that I need to blow up some CZ52s and remember the load [done that]. and I need to shoot hundreds of round in a Tokarev at considerably higher levels without incident [done that]

Further, I go for extra credit and figure out that what is limiting the CZ52 is a thin chamber on the bottom [done that].

Further, I compare results with a number of other pistols, and compare chamber wall thickness [done that] and find ..... big surprise here .... the unusually thin chamber is what makes the CZ52 sot weak.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Uncle Jaque calculates .050", so I may need to measure some more barrels.

http://www.gunboards.com/forums/uploaded/UncleJaque/2003111212344_CZ-52%20Barrl-Chmbr.Meas-071103.JPG

FWRA

November 13, 2003, 00:05

Clark---

That guy with the Timbs has no information on the CZ52 being stronger than the Tokarev. He is just making assumptions based on the crap that is written.

Really? Did you call him or is that another assumption? The fact that he specializes in hi velocity CZ52 ammo means he's just stupid and taking chances with his customers lives?

You better call him Clark. Don't assume anything.

Maybe he'll believe you and validate all your years of overloading CZ52's until they KB. A truly noble cause.....

FWRA

Clark

November 13, 2003, 10:20

I wrote to him:

"!!!!!!THESE LOADS ARE INTENDED ONLY FOR THE CZ-52 PISTOL!!!!!!"

Do you have any data to support this?
My data indicates that the Tokarev can take higher pressures than the CZ52.
The thin chamber bottom of the CZ52 splits before the brass fails.
I have tested many other pistols, and the CZ52 is the only one that fails like this or has a chamber so thin.

Queenie

November 13, 2003, 11:30

We are all waiting for his reply. I think you would do better with all this if you just confined your comments to the relative strengths of the Tokarev and CZ 52. By overstating your case you lose a lot of possible support. Looks to me like you might have discovered something. You should have been more careful about how you presented the findings and more forthcoming about your methods. Your tests still appear to be highly unscientific. There will always be legitimate doubts about the results.

FWRA

November 13, 2003, 19:05

Well what do you suppose Peter Cordona could respond to? An e-mail from a guy who's "personal testing" finds the CZ52 weaker than the brass and finds the Tokarev to be a stronger pistol? Who works for what independent testing agency?

Wow...

I say post here exactly the load that caused the catastrophic failure of this pistol time and time again. Also give us details of exactly how it was done. Did you hold the pistol in your hand...in a vise? Also, what was the condition of the barrels in those pistols? New...worn? Were these arsenal refinished pistols or original?

And if you are not prepared to tell us ALL the testing details? Tha will speak volumes and the Hell with "sent a private message" when someone else questions this. If you are going to jump on EVERY CZ52 thread ever posted with your stupid warnings then offer facts to back them up.

I don't know about the others on this board but I sure am tired of hearing about this.

And your comment..."sorry if this interferes with your business plan" or whatever. I like these pistols and specialize in them but sure don't sell 'em like the big distributors do. Why don't you write a letter campain to Century Arms who imports these by the thousands? Let them know what a dangerous design this pistol is and I'm sure they will pull all of them off the market immediately. (yeah...sure)

Or if you REALLY believe these are unsafe? do like Ralph Nader did with the Corvair. Only you take out a full page ad in Shotgun News and warn the public about the CZ52's shortcomings when handloads exceed the maximum recommended load.

If this is really about you being concerned about safety issues, a full page ad is the only way for you to proceed. How about it Clark...do you really care that much?

I doubt it. When someone has a question about CZ52's or 7.62x25 ammo you always deem it proper to chime in with your "CZ52 is unsafe" drivel just to stir up the pot.

However...if you truly want to give us factual data to prove your point, go here to do just that:
1-15-03 NOTE: I deleted that thread due to a lack of any serious attempt by Clark to give factual data
http://www.falfiles.com/forums/showthread.php?s=&threadid=92094

FWRA

Clark

November 13, 2003, 20:34

So when I ask the questions:
1) "Where did the books get the notion that the CZ52 is stronger than the Tokarev and C96?"
2) "Where is the data?"

Mostly I get no response. But here are a few:

--------------------------------------------

"Sierra's 4th" 1997, "Our test pistol was a Vz52....the Vz24 is an
extremely strong pistol... Reloads developed for pistols using less
robust locking mechanisms must be reduced drastically for safety
reasons. In recoil operated pistols, such as the Tokarev, starting loads
shown should be considered a maximum."

Subject: re: the strength of 7.62x25mm pistols
From: Rich Machholz rich@sierrabullets.com
Date: Fri, 21 Mar 2003 12:14:37 -0600
To: Clark

Clark,
Thanks for the information.
We would be interested in some details if you have time to share them. Obviously Kevin (the author) was referring to the locking mechanisms and not the barrels but we certainly are interested in your findings. They may save someone the experience you have had with these guns.
Rich

Subject: re[2]: the strength of 7.62x25mm pistols
From: Rich Machholz rich@sierrabullets.com
Date: Tue, 25 Mar 2003 15:35:05 -0600
To: Clark

Hi Clark,
Sorry about the delay but I was gone Monday.
Is this info available from a web site or directly from you?
It all looks interesting.
I don't see you on our mailing list either. If you'd like I'd be happy to put you on. All I need is your regular mailing address and a phone number. We send out a quarterly newsletter called the X-Ring.
Rich

Subject: re[2]: the strength of 7.62x25mm pistols
From: Rich Machholz rich@sierrabullets.com
Date: Thu, 27 Mar 2003 08:24:19 -0600
To: Clark

Clark,
Thanks for the offer of the handguns but we don't do much testing other than load work ups for the manuals and we just finished a year of that. I doubt if any of us would be willing to jump in and initiate another project in the immediate future. I am interested in your findings however.
Rich
-----------------
"Gun World" May 2003, Jan Libourel writes, "Pressures with this
cartridge [7.62x25mm] tend to run high, especially with some of the very
hot Czech loads designed for the sturdy vz52."

Subject: RE: "Libourel on Handguns" correction
From: "Gun World Magazine" editorial@gunworld.com
Date: Wed, 26 Mar 2003 17:54:29 -0800
To: "Clark

Thanks for the info. I have never done any shooting to speak with the
7.62x25, so I was just passing on the "conventional gunwriter wisdom" on
these matters. This is not necessarily the truth, as you point out. Thanks
for the info.
Cordially,
Jan Libourel

masman

November 13, 2003, 21:11

clark seeing you never answered my question on wether you thought the cz-52 is safe to use with factory ammo or with ammo using published data im going to assume that you think the pistol is safe under those circumstances.

Clark

November 13, 2003, 21:47

Here is some of my data from .1 gr. incremental work ups a few years ago:

2) 13.5 gr AA#9 is max AA book load, 86 gr FMJ, 1913 fps, 41.8k cup

a) 13.6 gr, CZ52, S&B brass .. OK

b), 13.7 gr, CZ52, Polish 55 Berdan brass [compressed load] .. Kaboom
[case head separation caused slide to split][bye bye $200 gun] 1%.

c) Polish Tokarev
b) 11.5 gr AA#5, 86 gr .54" S&B pull FMJ, 1.316", ex groove +.005", primer fell out, Quickload 93 kpsi, 35% overload

3) 11.7 gr AA#9 is max AA book load, 110 gr , 1688 fps, 42k cup

a) 13.7 gr splits a second CZ52 barrel and slide [bye bye $150 gun] 17%.

b) 13.8 gr in Chineese Tokarev, shakes trigger bar loose with stock recoil spring

c) 14.2 gr in Tokarev, Starline brass, primer falls out

d) 14.6 gr in Tokarev, Starline brass rim ripped off, failed to extract

e) 14.9 gr in Tokarev, Starline brass bulges and rim rips off.

f) 15.1 gr in Tokarev, OK with S&B brass

g) 15.3 gr in Tokarev, S&B brass, primer falls out. 31%

I have more data on trying to blow up Tokarevs with 110 gr bullets and N105, LONGSHOT, ENFORCER, AA#9, LIL'GUN, and Power Pistol. The Tokarevs are just too tough.

November 13, 2003, 23:52

MR Clark i am on a disabilaty income. i would love a cz52. so if you would you can give me one of your cz that you have not yet. blown up. that would make my day.so i will check my pm for your replay so i can send you my address.if you have that much money to blow up cz's you could spear one for a poor man~R

Queenie

November 14, 2003, 00:05

Clark
Member

FALaholic # 1213
July 02, 2003 07:42 Post #80

--------------------------------------------------------------------------------
Here is a synopsis of my 7.62x25 load development with WSP primers:

1) 15.3 gr H110, CZ52, 86 gr, S&B brass, ok, case full.

2) 13.5 gr AA#9 is max AA book load, 86 gr FMJ, 1913 fps, 41.8k cup

a) 13.6 gr, CZ52, S&B brass .. OK, more powerful than above H110 load

b), 13.7 gr, CZ52, Polish 55 Berdan brass [compressed load] .. Kaboom
[case
head separation caused slide to split] 1%.

3) 11.7 gr AA#9 is max AA book load, 110 gr , 1688 fps, 42k cup

a) 13.7 gr splits a second CZ52 barrel and slide [bye bye $150 gun] 17%.

b) 13.8 gr in Tokarev, shakes trigger bar loose with stock recoil spring

c) 14.2 gr in Tokarev, Starline brass, primer falls out

d) 14.6 gr in Tokarev, Starline brass rim ripped off, failed to extract

e) 14.9 gr in Tokarev, Starline brass bulges and rim rips off.

f) 15.1 gr in Tokarev, OK with S&B brass

g) 15.3 gr in Tokarev, S&B brass, primer falls out. 31%

4) No book loads available for these powders, I am just making up the
staring point, in Tokarev, 110 gr Hornady FMJ, 1.3", WSP primer,
Starline brass:

a) 17 gr LIL'GUN ok, case full

b) 12 gr N105, primer fell out, case almost full

c) 13 gr N110, ok, case full

d) 15 gr XMP5744, ok, case full

e)
10.5 gr LONGSHOT ok,
11 gr LONGSHOT .002" case head growth
11.5 gr LONGSHOT .002" case head growth, loose primer
12 gr LONGSHOT S&B brass and primer, .002~.003" case head growth
13.5 gr LONGSHOT S&B brass and primer, .002~.003" case head growth,
case full to mouth, most powerful of all the loads tried

[b]f) Revisited AA#9 and 110 gr: only 13 gr can chamber in a CZ52 without
OAL interference problems. CZ52 Pistol failures above were probably
caused in part by bullet lodging in riflings due to high bulk modulus of
AA#9.
Due to long throat chamber cut, 15.1 gr AA#9 will chamber in Tokarev
Pistol.

g) Ramshot Enforcer, Starline brass, 110 gr FMJ Hornady #3017 .684",1.390", compression required seater compensation from 12.8 gr but possible to 17.3 gr, WSP, C-96 4", Tok 4.55", CZ52 4.75"
a) 11 gr [42kpsi 1410 fps Quickload] good load
b) 11.3 gr pierces primer in C-96 [45kpsi, 1456 fps]
c) 13.1 gr, ok in Norinco 54, extractor grove expands .0005" [79kspi, 1747 fps]
d) 13.3 gr, ok, expands .001" [84kpsi, 1781 fps]
e) 13.7 gr, primer falls out, expands .0015" [96kpsi, 1850 fps]

5) "AA loading guide #2" 2000, 8.5 gr AA#5, 86 gr FMJ, 1.316", 1717 fps, Starline brass, CCI500, 41.5 kcup, ok in CZ52
a) 10.5 gr AA#5, 86 gr .54" S&B pull FMJ, 1.316", Starline brass, wsp, ok in Polish Tokarev
b) 11.5 gr AA#5, 86 gr .54" S&B pull FMJ, 1.316", ex groove +.005", primer fell out, Quickload 93 kpsi, 35% overload
c) 11.5 gr Power Pistol, 86 gr .54" S&B pull FMJ, 1.316", ok in Polish Tokarev, beats AA#5 in recoil, Quickload 107 kspi

6) Polish Tok
a) 9 gr Power Pistol, Starline, wsp, 1.316", 110 gr HNDY FMJ, ok
b) 10 gr Power Pistol, Starline, wsp, 1.316", 110 gr HNDY FMJ, primer falls out, +.015" ext
c) 10 gr Power Pistol, S&B primed, 1.316", 110 gr HNDY FMJ, ok, no ext groove change measureable

7) 18 gr LIL'GUN, Starline Supercomp brass necked down, 110 gr HNDY, wspm, ok, Lee Tokarev die too big, needs 9mm die help

-------------

--------------------------------------------------------------------------------
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OOPS! There's a little kink in the data. :sleep:

Clark

November 14, 2003, 00:48

I don't seem to be able to hurt any other pistols but overfilling the case and ramming the bullet into the lands.
It does make the pressure go higher and the brass failure more likely, but the other pistols, like the Tokarev, seem to survive with 15.3 gr, the bullet jammed in the lands, and the primer falling out.

I could blow up another CZ52 [I have a few more] with AA#5 or some other powder and then show it will not blow up a Tokarev, but we would be right back here.

Touch the lands or not, the others survive, the CZ52 splits the barrel.

What do you want me to do?
I have limited time and budget, and the books are wrong.
I can't do an exhaustive study for every concern anyone might have.
Those that print books that are wrong should bear some responsibiltiy, shouldn't they?

Sierra doesn't want to run the tests.
You can bet Quality Cartridge has no facilities.
AA does't want me to send them CZ52s and Tokarevs.
How am I ever going to get the books corrected?

Queenie

November 14, 2003, 01:20

Did the CZ KB because of the "bullet lodging in riflings" or not?

Oh well, the sad truth IMHO is your favorite passtime is for the most part irrelevant. If you can repeat, consistently, your destruction with the 1% overload, then AA definately needs to look at your data and re-evaluate their work-ups. It really doesn't seem though that there is a serious problem with the CZ and KB's. It would have manifested itself by now more times than what has occured. As for the books...good luck.

Clark

November 14, 2003, 09:44

It has been my experience that anything that prevents the bullet from starting raises the pressure.
For instance the max load in 9mm with 158 gr. and Power Pistol would be about 5.3 gr.
http://recipes.alliantpowder.com/rg.taf?_function=pistolrevolver&step=2&bulletID=23&cartridgeID=1014&caliber=9mm&cartridgedescr=Luger&bulletdescr=147%20XTP
At 8.5 gr. [60% overload] the primer will pierce and one would think that the load can go no higher.
But with a different procedure:
1) The powder is first compressed with a pin gauge in a collet bullet puller.
2) The bullet seated
3) The loaded round is resized with a sizing die with the decapping pin removed.

With the different procedure, the load can be increased to 11 gr. [107% overload] and then stopped because the powder will compress no more.

This trick would work for 5 of my 9mm pistols, but I am suspicious it would blow a CZ52 9mm barrel because of how thin the chamber walls are.
--------------

Having overloaded three dozen calibers in many gun designs to see what happens, I can tell you that rimless cases are weaker than rimmed cases.
The rimless case expands in the extractor groove [no guns support it there] and the primer pocket expands a few thousands. The primer then falls out.
This failure in semi auto pistols may be masked by brass bulging down the feed ramp if the feed ramp is cut past the case web.

There are many revolvers that will split the cylinder at the point where the chamber walls are thin, with a pressure below what it would take to make the primer fall out of a rimless case. But there is only one semi auto pistol I am aware of that is so weak that it will fail at a pressure below what it takes to make the primer fall out. That single weak semi auto design is the CZ52.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Clark

November 15, 2003, 13:20

I have exchanged email a couple times with Peter at Quality Cartrige.
He is a real nice guy, but the "CZ52 only" sign on his web site does not come from Tokarev testing. He has done testing to convince himeself the loads he sells are safe in CZ52.

Jambo

November 15, 2003, 15:42

I really wasn't planning on getting involved in the shit storm that this thread turned into, but here it goes:

I agree that the thin area of the chamber wall does limit the different loadings for this gun, but most people aren't going to intentional load the CZ52 that high. If it's possible, try and figure out the pressure produced by the 13.7 grain loading just to give everyone an idea of how much pressure the CZ52 can take. I do have a few questions: did you test 2 or 3 (or more) CZ52's or is your data based off of just one CZ52.
Also, I noticed this:

a) 13.6 gr, CZ52, S&B brass .. OK, more powerful than above H110 load

b), 13.7 gr, CZ52, Polish 55 Berdan brass [compressed load] .. Kaboom
[case head separation caused slide to split]

Why did you use different brass?

Clark

November 15, 2003, 17:42

Jambo,
And I agree with you.
The switching brass was because I ran out of virgin S&B that day.
In retrospect, I wish I had waited.

I have just blow up two CZ52s, and I have a few more.
I have not blow up the rest of them because I have been offering to send them and Tokarevs to AA, Sierra, and one who will test the Tokarev vs CZ52 to the death, publish, and print the pressures it took.

Jambo

November 15, 2003, 17:58

I'm not really taking sides at this point, but it does sound like the Tokarev is stronger than the CZ52 as far as the chamber wall thickness goes, at the bottom anyway. I think that if the design was tweeked with a little, like make make the slide and barrel a little taller to allow for more meat in the thin area, it would be a hell of a better gun and would, of course, survive higher chamber pressures. Am I making any sense?

gunnut1

November 15, 2003, 18:36

I really think the real question here should be wheather the CZ52 will blow up with normal-store-bought loads. I am so worried about it that I just bought 200 rounds of Polish 7.62x25 for my CZ52.

Jambo

November 15, 2003, 18:47

Hey Clark, that gives me an idea: You ought to test surplus 7.62x25 ammuntion in the CZ52. You know, see what all is safe the shoot in the CZ52, since surplus ammo isn't always the safest.

masman

November 15, 2003, 19:20

Originally posted by gunnut1
I really think the real question here should be wheather the CZ52 will blow up with normal-store-bought loads. I am so worried about it that I just bought 200 rounds of Polish 7.62x25 for my CZ52.

forget it gunnut1 i've asked him that question twice and he refuses to answer it.btw that polish ammo is good stuff:biggrin:

Clark

November 15, 2003, 20:02

Jambo,
You make sense to me.
A Steven break action .410 can take allot more pressure than a Ruger 454 Casull revolver, because thick walls mean more than what load books say.

Masman, I bought hundreds of pounds of Polish when it was 7 cents delivered from Century and I was in the top 1% of engineering income.

Now for barter [I have done more handi man labor this year than engineering, thank you dotcom buble], sometimes I take a tin to gun stores and trade at 7 cents a shot. It all goes off, but the velocity is between 1450 and 1550, where my CZ52s will only set of 80% of the Czech ammo on strippers, but they are all 1550 fps.

7idl

November 16, 2003, 02:18

Originally posted by Jambo
Hey Clark, that gives me an idea: You ought to test surplus 7.62x25 ammuntion in the CZ52. You know, see what all is safe the shoot in the CZ52, since surplus ammo isn't always the safest.

you mean.... provide some "useful" information...

HMMMMMMMMMMMMMM

you may be on to something here!!!!!!

:cool:

Clark

November 16, 2003, 12:58

My contention is that the CZ52 is fine with factory loads and book loads, but the books that say the CZ52 is stronger than the Tokarev are wrong.

Practical information would be to tell the Tokarev owners that they can INCREASE, not decrease the CZ52 loads.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

masman

November 16, 2003, 13:44

Originally posted by Clark

Practical information would be to tell the Tokarev owners that they can INCREASE, not decrease the CZ52 loads.

true and i have no idea why you havent been pushing that fact.i have two theories why the cz-52 has been touted as being stronger than the tokarev.the firest one is.popular lore of the cz-52 is that the czechs were upset at moscow telling all warsaw pact countries they had to have the same ammo.so they made the pistol stronger than the tokerev to handle a hotter load that would blow up a tokerev.second is that the tokerev has seen harder use than the cz. so alot of them might not be in the greatest shapelike the cz-52's.its kinda like winchester and remington downloading 8x57 ammo because they're covering their butts just incase somebody decided to shoot some ammo in a world war one relic.

FP1201

November 16, 2003, 20:54

Just a couple thoughts here:
1) While developing loads for the 445 Super Mag. I consulted an engineer from the powder company who said "...the published loads are reduced by 10% from the maximum..." This was done to minimize the risk/liability of publishing loading data. The name of the company is not disclosed because I was told in confidence, and agreed not to blab. I will say it was one of the powders used in CLARKs testing.

2) I would accept the wall thickness of the CZ52 being less than the T-33 and therefor possibly weaker, but is the metalergy of the two pistols the same?
ie: a 1/4" grade 8 bolt is stronger than a 5/16" grade 3 bolt.
How much of the chamber is .060 thin? Certainly 1/8" of the case is un-supported in 1911 pistols...of course the case usually blows out before the barrel splits.

3) Military brass is a whole diffrent world from commercial brass, as well as the resulting pressures from diffrent types, manufacturers, and models of primers.

4) A remark was made about the CZ's "slipping thru safety testing, prior to importation" Who requires this, and where can a report of the testing be located?

All in all, I plan on ordering three CZ's from Century this week as they are 3 for $309 this month with free shipping. I'll also order dies, brass, and even some facory ammo.
After reading this thread and several others, the point CLARK is making is: The books are wrong with the statement: "the CZ52
IS stronger than the Tokerev". The other point that's been proven is: If you overload and/or use incorrect powders in your reloads you'll be saying "WTF happened" and "Am I bleeding?":tongue: