7.62x25 what's the point?

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penetrate

I don't know about the others you mention, but the 7.62 X 25 will penetrate both panels of a ballistic vest, as tested by me.
 
Thanks for the links guys, it was somewhat enlightening. It seems the main takeaway is that the weaker CZ barrel fails at "only" 42,000psi :rolleyes:. The pressures I found in a quick search for reccomended maximum were around 35,000 psi.

He also mentions that at the heavy loadings, the bullets were pressed up against the rifling in the CZ since it's chamber throat is shorter than the tok (apparently). I can't help but wonder if that causes the pressures to spike higher, faster in the CZ than in the Tok, exacerbating the weakness in the barrel. Does anyone know how thick the CZ chamber is at it's narrowest area? If it's more than 1/10" or so, the failure is probably more due to the sharp corners in the roller pockets creating stress concentrations than anything. It's truly moot, though, since Clark had to use loadings that couldn't satisfy OAL requirements in the CZ to cause it to fail. Who in their right mind would cram so much powder into a case you can't seat the bullet properly?

I don't know about ya'll, but I would never push a cartridge past its reccomended maximum (especially if that max is already north of 35K!), let alone 20%. Both pistols are strong well past insane loadings. If you're counting on your pistol to save you if you screw up your reloads, you're a damn fool.

TCB
 
barnbwt said:
Thanks for the links guys, it was somewhat enlightening. It seems the main takeaway is that the weaker CZ barrel fails at "only" 42,000psi :rolleyes:. The pressures I found in a quick search for reccomended maximum were around 35,000 psi.

OK but bear in mind that's only 10k psi from CIP maximum to "blows up in your face" . Now chamber a round three or four times and get yourself about .050" of bullet setback.

http://i27.tinypic.com/aw8h8k.jpg


Still seem like plenty?


I don't know about ya'll, but I would never push a cartridge past its reccomended maximum (especially if that max is already north of 35K!), let alone 20%. Both pistols are strong well past insane loadings. If you're counting on your pistol to save you if you screw up your reloads, you're a damn fool.

Remember you bought this gun to shoot super cheap 45yo + ex communist bloc surplus made by disasatisfied dissidents and cared for in ? ?? manner. Does a mere razors edge 7000psi saftey margin still seem plenty?

TCB
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My point is that 7000 psi is NOTHING with lots of outside factors that could bring about this much overpressure. A point at wich a CZ52 doesnt beat the slide stop up or wear faster as it would were it a safe pistol design it BLOWS UP

Look at it this way no 9mm handgun made since wwII will BLOW UP at only 42k psi nor will so converted tokarevs. Now would you shoot +p a cz52 converted to 9x19?
 
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Im sorry but I just cant take the 42,000psi failure as gospel unless it comes from an accredited testing lab. There is too much false information on the internet. This guy may be an honest man or not it doesnt matter, there are too many factors we dont know. I mentioned bore size earlier. My TT-33 has a .311 bore my vz-cz has a .308. this will have different pressure. was he using .308 bullets? sized down 3.12 bullets? (alot of folks load them). Also there were several aftermarket barrels offered after these pistols were imported. some from less than reputable sources (unknown makers). Tell you what find one person that has had the chamber blown out of their cz-vz52 and I might worry. Remember there are hundreds of goofs out there loading this load with .32 acp bullets and using finish data as a starting point. I would think 42,000 has been breached daily, yet other than "Clark" I havent heard of a single exploded pistol.
 
Back to ammo

I think now is a good time to re post some surplus ammo with known pressure problems This is the dreaded Bulgarian surplus . If you have any of this in your stock it would be wise to dispose of it properly its not safe in any pistol from what Ive seen posted (several sources). As far as I know this is the only bad year (1952), and other Bulgarian is ok.
 

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coalbed said:
Tell you what find one person that has had the chamber blown out of their cz-vz52 and I might worry. Remember there are hundreds of goofs out there loading this load with .32 acp bullets and using finish data as a starting point. I would think 42,000 has been breached daily, yet other than "Clark" I havent heard of a single exploded pistol.
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You haven't looked around hard enough. Numerous CZ-52s have been blown up with milsurp ammo.
 
Ill look again. If you know of a case where the owner is posting it and not just something they read, I really would love to read it. As I said I have 4 of them, and while Im not the prettiest man in the world, Id like to keep my face.
 
I also load this round, I keep them well within pressure limits. One reason I like the vz-cz52 over my tok is its very smooth shooting and accurate, and thats my goal in loading, accuracy. I even considered having dovetails milled in my favorite to use some of the fine 1911 sights.
 
Looks like I was wrong there are some that blew up with surplus, however Im still going to say this, you run a risk in every firearm using old surplus ammo from any country, and I could post pics of almost every firearm known failing. even Remington is in court right now over injuries sustained when 700 series rifles fired on their own. They have sold over 5 million of these rifles and have a good name. thats just one example. Are we to throw out our 700's ? the 1st post you show, the guy using surplus (looked for it not shure what it was) had a jam, cleared it, the blew his slide. If you have a jam using old ammo, you better look down the bore and see if you have a bullet in the barrel. vz-cz52's dont jam, at least none of mine do, so that would be a good clue something is terribly wrong.
 
I also load this round, I keep them well within pressure limits. One reason I like the vz-cz52 over my tok is its very smooth shooting and accurate, and thats my goal in loading, accuracy. I even considered having dovetails milled in my favorite to use some of the fine 1911 sights.
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I've done "machine work" (if you're being charitable :rolleyes:) on my slide to add a tenon front sight. You either have to really want that alteration, or be willing to pay extra to have someone else do it (I recommend the latter). The slide is about as hard as glass. I burned the tips out on two chrome-moly bits before trying a carbide bit. It took around 20lbs on the bit to get it to bite at all, and two carbide bits to get through, ultimately. The "shavings" were tiny sharp splinters, and in breaking sounded exactly like I was drilling glass. I think the biggest factor going against the CZ is metallurgy, moreso than mechanical design. If I had extra CZ's laying around that I didn't want, I'd want to test dropping some slides on a hard surface; that would be interesting.

you run a risk in every firearm using old surplus ammo from any country...cz52's dont jam, at least none of mine do, so that would be a good clue something is terribly wrong
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Agreed. The only times I've had a FTF were from hammer follow (me hitting the decocker under recoil), and a dud. Each time, I carefully scrutinized the situation, since it was so uncommon for the gun to jam. I've probably put around 300 rounds through mine (S&B and Bulgarian(?) surplus), and only 2 failures. The last 2/3s are with the heavy 18(?)lb Wolff spring, which makes the slide cycle much less wonky. I'd wager that all documented milsurp kabooms were caused by squibs or the Bad Bulgy, and neither the CZ nor TT do well in those instances.

*crypt keeper* "Beware the 3-10-52 headstamp...":D

Im sorry but I just cant take the 42,000psi failure as gospel unless it comes from an accredited testing lab.
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I agree with this as well. We have no idea of the history the *only* two pistols used in the test, and how they differ from the ones we own. Being only two "data" points, no statistical proof can be taken from this misadventure. The only thing I think it's useful for, is to show that overloading an already hot-rodded round is stupid. We all know not to put .357 mag in .38sp, and not to put .357max in a .357; why is it so unreasonable to expect the same from a CZ?

One of those "kabooms" posted is failure at the front of the slide, where, as I said, it is very brittle (probably fatigued from bad recoil spring). Another blew out the chamber, frame, and slide (am I really to expect a TT would be unphased?) The third was a guy reposting others' kabooms. All appear to be from "CZ vs TT" threads ;). None reportedly injured the shooter (despite blowing out at the bottom of the chamber).

Although there was this gem:

For some reason, each gun has something of a militant, cult-like following that irrationally bashes the other gun
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Sounds like another small-caliber hot-rod round debate we all know about...I don't think it's wise to overload a 5.7x28 beyond spec, either, FWIW ;)

TCB
 
Ime there are three types of 7.62x25 owners

People whose only owned the cz

Tt33 only owners

And those like me whose owned both.

Its my observation that owners of both eventually become TT33 only shooters. And that cz52 owners will tend to become shooters of both given time progressing to the tokarev.

The cz52 is the x25 gateway drug. The tokarev is the "hard stuff"

;)
 
From one of the sites referenced:

TT-33 chamber at thinnest is .125"

CZ-52 chamber at thinnest is .058

Since .075" is the thickness of a S&W K-frame in .357mag (a more powerful, and larger diameter cartridge handgun with threads cut in the barrel. Measurement courtesy of RCmodel on another forum here), I'll go out on a limb and say the CZ-52 chamber is adequate for the cartridge. IIRC, .030" or so is all that's needed to contain just the pressure of a SAAMI .357.

Without knowing the strength allowables of the steels in either gun, or the affects of stress concentrators, the relative strength of both platforms cannot be known (just that the CZ-52 chamber fails first, based on limited experiments). Besides, any permanent plastic deformation in a gun is considered a failure; I believe Clark noted that the TT was stretching in some places at the hot load levels, just not rupturing. I'm still more interested in which gun fails fastest with proper-to-slightly hot ammo, and how.

Ime there are three types of 7.62x25 owners
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You may be right, but where do you get a TT33 for 200$ (what I paid about 4 mos ago)? They're both fun guns, but hardly practical compared to more modern offerings, and as the prices rise, there is less and less incentive to muss with them (until some enterprising company puts out a Poly or Hi-Power chambered for 7.62x25). The CZ is probably the only toe I'll dip in the water, until my ammo dries up, and I can sell it for ~double what I paid (not too long now...)

PS-there's a fourth type: the PPSH owner, but I don't know much about them (very ellusive ;))

TCB
 
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barnbwt said:
CZ-52 chamber at thinnest is .058

Since .075" is the thickness of a S&W K-frame in .357mag (a more powerful, and larger diameter cartridge handgun with threads cut in the barrel. Measurement courtesy of RCmodel on another forum here), I'll go out on a limb and say the CZ-52 chamber is adequate for the cartridge.
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The 357 Mag might be more powerful and a larger caliber, but the only thing that matters is pressure. The pressure limit for 357 Mag is the same as for 7.62 Tok, and as you point out the chamber wall is nearly 30% thinner.
 
CZ-52 chamber at thinnest is .058

Since .075" is the thickness of a S&W K-frame in .357mag (a more powerful, and larger diameter cartridge handgun with threads cut in the barrel. Measurement courtesy of RCmodel on another forum here), I'll go out on a limb and say the CZ-52 chamber is adequate for the cartridge.
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The 357 Mag might be more powerful and a larger caliber, but the only thing that matters is pressure. The pressure limit for 357 Mag is the same as for 7.62 Tok, and as you point out the chamber wall is nearly 30% thinner.
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30% thinner and made from an unknown alloy too.

357,9x19 and 7.62x25 all operate at 35k psi


9mm +p actually has the highest pressure of the three at 38k psi
 
I think that the only reason why .357 SIG is included in the list is because it's a bottleneck cartridge. .357 SIG has ballistics that are near .357 magnum and is used as a general purpose round.

5.7x28 is more of a specialized round meant for mostly subguns for armor piercing.

7.62x25 I believe was made to standardize production with the Russians during war considering how most if not all arms that were standard issue were .30 caliber. Easy to make barrels for different guns if they all are the same bore size.

Never fired one or seen one fired in person but I hear that 7.62x25 has a heckuva muzzle blast and flash. :)
 
It's a heckuva fun round, FIVETWOSEVEN, it's just getting more expensive, with painfully little interest in modern development from industry. You should try to find an opportunity to shoot it sometime; It's got the flash, bang, and flat trajectory of a magnum loading, but fairly mild recoil; pretty much like a 327mag for autos.

It is weird how the Russians insisted everything be chambered in the same caliber, and that probably had more to do with stupid military stubborness than anything ("there never was, is, or will be any'ting better than the 7.62 caliber"). Considering the rifling and rest of the guns are all unique, a shared barrel inner diameter couldn't save that much labor, right? :scrutiny:

30% thinner and made from an unknown alloy too.
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Like I said, given the numerous known issues of metallurgy in the CZ, I think the alloy strength/brittleness is probably more of a limiting factor than the design itself. Bear in mind that a revolver barrel (S&W especially) has to be considerably beefed up to have threads cut in it, take the added stress of torquing crush-threads, and impacts of bullets on the forcing cones. One of the niceties of semi-autos is they are exempt from all three of those issues. Not saying the CZ is weaker than the TT, just that it isn't underdesigned (and dangerous).

The 357 Mag might be more powerful and a larger caliber, but the only thing that matters is pressure.
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The larger bore absolutely matters. The formula for hoop stress in a thin ring (a bad approximation for a relatively thick, complicated shape like the chamber, but the general relation of the factors to stress is the same) is:

F=PR/T

R/T for the CZ is: 5.31 (.308/.058)
R/T for the K-frame is: 4.76 (.357/.075)

The hoop force developed in the K-frame is effectively 10% lower than the CZ. The stress (more important factor) relation can't really be guessed since we don't know the alloy (or consistency) of the CZ. For all we know, the CZ alloy may be stronger than the S&W, but more brittle, and prone to "spectacular" failure. And like I said, the above formula is innaccurate for this case. You'd need to do FEM (and strain-guage testing) to know for sure. But the question is more complicated than a simple direct relationship between chamber thickness and rupture strength, and the difference between a known "safe design" and the "unknown" CZ is probably a lot less than we think. That the TT is obviously very overbuilt has nothing to do with whether the CZ is safe (since we've established the TT is capable of handling hotter loads in a single firing).

Sorry for the stress-analysis diatribe, but I'm in the middle of napkin-calculations on my own mad scientist project :evil:

TCB
 
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Walking Dead said:
do why wouldn't you just buy a new gun in 9mm, 5.7 or 357 Sig?
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You gave me a great idea. Leasing guns. Instead of dropping $500 on that new glock you can take one home for low monthly payments and just bring it back when the new gen models come out. Never be stuck with an outdated gun again.*****

******Offer excludes tax, title, and background check. Not available in Cali, D.C., NYC, or Chicago. Void where prohibited. Annual round fire rate of 100 rounds, $0.10 a round due when lease ends.
 
The original post was the attraction of the 7.62 x 25 Tokarev round. I was a guest in Hungary in 1968 and watched a Red Army team demo the Russian Tokarev and ammo. If you would have been there, you would know why I own a Tokarev and not a 1911 pistol.

You just had to be there I guess is the reason,

blindhari
 
I have always personally wondered what the firearms world would be like if a similar cottage industry had sprung up for the Tokarev as for the 1911. It's an interesting mental exercise, for sure. Anyone want to imagine a "enhanced" TT-33?
 
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