My CZ-52 pistol exploded in my hand today...
Bryan C.
night without noticing anything unusual, and had already put 60 rds
through it when it blew. I was on my last box of Sellier & Bellot
7.62x25, and had not seen any problems with the previous 460 rds of
the lot I had purchased. When it blew the slide did not cycle, and
the barrel split from the chamber forward for about 3". It also took
out a 3" piece of the slide from the ejection port forward, which flew
about 3'. The slide was twisted up off the rails, and the frame plate
below the slide on the right side twisted out. The gunsmith confirmed
the gun was a loss, and feels it must have had an obstruction in the
bore. I don't think it did, the recoil is pretty stout and I sure
didn't notice a squib. Oh well, at least no one was hurt. Now I am
looking for a good deal on another CZ-52, since I have just bought new
mags and ammo. I did love the gun.
-----------------------------------------------------------
Learn about rec.guns at http://www.recguns.com
-----------------------------------------------------------
Clark Magnuson
Last week I tried to reproduce those effects and found that AA#9, with a
high bulk modulus [will not compress], pushed the bullets back out. This
made an OAL in excess of 1.3". The CZ52 has a very short throat. I now
believe this bullet interference contributed to the unusually low safety
margin I measured in the CZ52: 17% overcharge.
Joseph Oberlander
#
# Yep, my CZ-52 exploded in my hand today. I just cleaned the gun last
# night without noticing anything unusual, and had already put 60 rds
# through it when it blew. I was on my last box of Sellier & Bellot
# 7.62x25, and had not seen any problems with the previous 460 rds of
# the lot I had purchased. When it blew the slide did not cycle, and
# the barrel split from the chamber forward for about 3". It also took
# out a 3" piece of the slide from the ejection port forward, which flew
# about 3'. The slide was twisted up off the rails, and the frame plate
# below the slide on the right side twisted out. The gunsmith confirmed
# the gun was a loss, and feels it must have had an obstruction in the
# bore.
My guess is that this did happen. Unfortunate, but thankfully you are
okay. You probably had one with primer only go off. OTOH, handloading
will solve this :) A nice pasttime to get into.
Dan Meadows
wouldn't cycle my CZ52 about half the time. Still, surely you would have
noticed a squib. Especially since a squib load would fail to eject. This is
a real mystery. You have my condolences....DanM
Charles Winters
pistols. About a year ago, one blew up at the local rifle range in my
town. A bystander was hit in the head by a flying piece of metal and
had to go to the hospital. The police came and closed the range for
several hours while they investigated. I don't know what the
circumstance were, whether it was a hot reload, questionable milsurp
ammo, a squid with a lodged bullet in the barrel or just a defective
pistol. All I know is, after all these failures, I would not fire one
and don't even want to stand next to one when its fired. - CW
Joseph Oberlander wrote:
> ...
200...@wongfaye.com
Tom Line
flinches?
Wilbur
I have shot Norinco ammo, new manufactured S&B and at least one other brand
(don't remember who) and the new S&B was noticeably hotter than either of
the other two. Not as hot as the M48(?) surplus made specifically for the
CZ-52 I hear, but still plenty hot.
"Dan Meadows" <dan...@concentric.net> wrote in message
news:afn03t$iuv$1...@grapevine.wam.umd.edu...
# S&B 7.62x25 is probably the mildest ammo available in that loading. It
# wouldn't cycle my CZ52 about half the time. Still, surely you would have
# noticed a squib. Especially since a squib load would fail to eject. This
is
# a real mystery. You have my condolences....DanM
Keith Whaley
Charles Winters wrote:
#
# Not sure what is going on here, but something is amiss with these CZ-52
# pistols.
You don't know what is going on, but you DO know something is amiss.
Hmmm.
# About a year ago, one blew up at the local rifle range in my
# town. A bystander was hit in the head by a flying piece of metal and
# had to go to the hospital. The police came and closed the range for
# several hours while they investigated. I don't know what the
# circumstance were, whether it was a hot reload, questionable milsurp
# ammo, a squid with a lodged bullet in the barrel or just a defective
# pistol. All I know is, after all these failures, I would not fire one
# and don't even want to stand next to one when its fired. - CW
Gee, I once knew of a Chevy Corvair that flipped over, and I am glad I
don't have to ever worry about driving one!
I don't know WHY it flipped, but still...I'd never drive one myself.
They're dangerous!
I know of a VW bug that did the same thing. I'm never going to drive
one of those, either.
I hear about a Glock that blew up. I'll NEVER shoot one of those
dangerous guns! Shudder!! They blow up on you!
I knew a guy who cut off his finger with a Craftsman radial arm saw.
Bad, bad machine. I'll never buy one of those, let alone use one. I
may never buy Craftsman again, for that matter!
A friend of mine lost his fingertip to a meat slicer, when he was
working at the local butcher shop.
I don't think I'll eat sliced lunch meat again! Ever!
# Joseph Oberlander wrote:
# > ...
Keith Whaley - pistolsmith
WHALEY's Gunsmithing
Los Angeles, CA
Clark Magnuson
Charles Winters wrote:
About a year ago, one blew up at the local rifle range in my
# town. A bystander was hit in the head by a flying piece of metal and
# had to go to the hospital.
#From what I have seen of CZ52 explosions, I would guess the victim was
on your right, and was hit with part of the extractor. If so, he is
lucky he was not killed. I have seen the extractor go through allot of
material, sideways.
MTNMANN
hotter than pistol ammo.
Just a thought, not a fact.
Mtnmann
Bryan C.
> ...
Didn't stop me from continuing to shoot that day...in my case no effect.
Wilbur
only two I've heard of, other than people deliberately trying to blow them
up. And since Mr. Oberland isn't sure what happened in his case and you
don't have a clue what happened in the one you cite isn't it just a little
hysterical to suggest all the guns are defective? I frequent several message
boards with many owners of CZ-52s and have one myself and I've seen no
reason to believe there is something inherently wrong with the gun. In fact
I've heard of a lot more Glocks blowing up. The police range in my hometown
has had 4 Glocks blow up on the firing line in the last few years. Since I
don't know for sure what caused them do you recommend everyone quit shooting
Glocks until I can find out?
"Charles Winters" <ch...@mindspring.com> wrote in message
news:afod2j$3tj$1...@grapevine.wam.umd.edu...
# Not sure what is going on here, but something is amiss with these CZ-52
# pistols. About a year ago, one blew up at the local rifle range in my
# town. A bystander was hit in the head by a flying piece of metal and
# had to go to the hospital. The police came and closed the range for
# several hours while they investigated. I don't know what the
# circumstance were, whether it was a hot reload, questionable milsurp
# ammo, a squid with a lodged bullet in the barrel or just a defective
# pistol. All I know is, after all these failures, I would not fire one
# and don't even want to stand next to one when its fired. - CW
Clark Magnuson
#
# Gee, I once knew of a Chevy Corvair that flipped over, and I am glad I
# don't have to ever worry about driving one!
# I don't know WHY it flipped, but still...I'd never drive one myself.
# They're dangerous!
#
# I know of a VW bug that did the same thing. I'm never going to drive
# one of those, either.
# I hear about a Glock that blew up. I'll NEVER shoot one of those
# dangerous guns! Shudder!! They blow up on you!
# I knew a guy who cut off his finger with a Craftsman radial arm saw.
# Bad, bad machine. I'll never buy one of those, let alone use one. I
# may never buy Craftsman again, for that matter!
#
# A friend of mine lost his fingertip to a meat slicer, when he was
# working at the local butcher shop.
# I don't think I'll eat sliced lunch meat again! Ever!
There is a difference between perceived risk and calculated risk.
Gun control advocates depend on triggering a perceived risk reaction,
and gun rights proponents counter with a calculated risk point of view.
The Chicken Little / Nervous Nellie of the gun culture is the perceived
risk of gun blowing up. If I tell someone I proof tested a gun with a
trigger string, a common reaction is, "You had better have your life
insurance paid up, because you can't get a string long enough!"
Here are the causes of premature death world wide for the last century:
1) Disease
2) murdered by gun control government
3) war
A good precaution for the big risks is to live in the good old USA.
Keith Whaley
pistol ammo.
They do not usually make it stronger at all.
It's the longer barrel of the sub-gun that provides greater speed,
hence greater delivered energy.
Keith Whaley - pistolsmith
WHALEY's Gunsmithing
Los Angeles, CA
MTNMANN wrote:
#
# Perhaps this person was using submachine gun ammo which is supposed to be a bit
# hotter than pistol ammo.
#
# Just a thought, not a fact.
#
# Mtnmann
FBC3
Is this for sure? Could a weak load have enough pressure to function the
action while sticking a bullet in the barrel?
Yoss...@mindspring.com
<ch...@mindspring.com> wrote:
Never seen one blow up, but I did see a cz-52 extractor and spring
shoot out along side an expended cartridge case once. The shooter
decided then that it was time to retire that pistol. It was only the
second mag he had run through it also. Other than that personal
experience, I have heard only positive things about them.
Adam Kippes
# Here are the causes of premature death world wide for the last century:
# 1) Disease
# 2) murdered by gun control government
# 3) war
# A good precaution for the big risks is to live in the good old USA.
Which, as we all know, does not engage in any gun control. No, sir.
-- AK
--
Please reply to the newsgroup. That is why it exists.
Marek Stanek
is significantly hotter and loaded with heavier steel-core bullet. The
difference is about 200 Joule of muzzle energy, boosting it up to more
than 900 Joule. The chamber pressures are also more than 30% higher,
exceeding even tormentation pressures for pistols.
I can dig out the ballistic data when I come home, if you wish.
Mark
"Keith Whaley" <kei...@dslextreme.com> píąe v diskusním příspěvku
news:afti5t$m17$1...@grapevine.wam.umd.edu...
# Far and away most sub-gun ammo is not at all different from
as-issued
# pistol ammo.
# They do not usually make it stronger at all.
# It's the longer barrel of the sub-gun that provides greater speed,
# hence greater delivered energy.
#
# Keith Whaley - pistolsmith
# WHALEY's Gunsmithing
# Los Angeles, CA
#
#
# MTNMANN wrote:
# #
# # Perhaps this person was using submachine gun ammo which is
supposed to be a bit
# # hotter than pistol ammo.
# #
# # Just a thought, not a fact.
# #
# # Mtnmann
#
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Henry E Schaffer
##since a squib load would fail to eject.
#
#Is this for sure? Could a weak load have enough pressure to function the
#action while sticking a bullet in the barrel?
I did some testing of very light loads in a Beretta 92. As the loads
got lighter first I got stovepiping, then the slight would move back
enough to trap the case between the slide and barrell, then to just
expose part of the case but end up with it in the chamber and finally
(with the lightest loads I tested) to not have the slide move back
visibly.
But in all of the experiments the bullet went out of the barrel and
hit the 50 yard berm.
--
--henry schaffer
h...@ncsu.edu
Brian P Burke
"Keith Whaley" <kei...@dslextreme.com> wrote in message
news:afpkf3$bfu$1...@grapevine.wam.umd.edu...
#
# Charles Winters wrote:
# #
# # Not sure what is going on here, but something is amiss with these CZ-52
#
# You don't know what is going on, but you DO know something is amiss.
# Hmmm.
#
# # About a year ago, one blew up at the local rifle range in my
# # town. A bystander was hit in the head by a flying piece of metal and
# # had to go to the hospital. The police came and closed the range for
# # several hours while they investigated. I don't know what the
# # circumstance were, whether it was a hot reload, questionable milsurp
# # ammo, a squid with a lodged bullet in the barrel or just a defective
# # pistol. All I know is, after all these failures, I would not fire one
# # and don't even want to stand next to one when its fired. - CW
#
# Gee, I once knew of a Chevy Corvair that flipped over, and I am glad I
# don't have to ever worry about driving one!
# I don't know WHY it flipped, but still...I'd never drive one myself.
# They're dangerous!
That's what Ralph Nader said, anyway. I always thought they were cool,
especially the convertibles.
# I know of a VW bug that did the same thing.
I haven't, but I've know plenty of them to catch on fire.
I'm never going to drive
# one of those, either.
# I hear about a Glock that blew up.
I've never heard that. What was the serial number?
I'll NEVER shoot one of those
# dangerous guns! Shudder!! They blow up on you!
# I knew a guy who cut off his finger with a Craftsman radial arm saw.
# Bad, bad machine. I'll never buy one of those, let alone use one. I
# may never buy Craftsman again, for that matter!
Ever?
# A friend of mine lost his fingertip to a meat slicer, when he was
# working at the local butcher shop.
# I don't think I'll eat sliced lunch meat again! Ever!
Don't blame you. Who wants fingertips?
Keith Whaley
Marek Stanek wrote:
#
# With 9mm Luger that's right, but not with 7.62x25 TT. The sub-gun load
# is significantly hotter and loaded with heavier steel-core bullet. The
# difference is about 200 Joule of muzzle energy, boosting it up to more
# than 900 Joule. The chamber pressures are also more than 30% higher,
# exceeding even tormentation pressures for pistols.
# I can dig out the ballistic data when I come home, if you wish.
# Mark
And who makes that ammunition, Mark? County and manufacturer? Even
headstamp stamps would be very much appreciated.
Thanks, keith whaley
#
# "Keith Whaley" <kei...@dslextreme.com> pí1e v diskusním příspěvku
# news:afti5t$m17$1...@grapevine.wam.umd.edu...
# # Far and away most sub-gun ammo is not at all different from
# as-issued
# # pistol ammo.
# # They do not usually make it stronger at all.
# # It's the longer barrel of the sub-gun that provides greater speed,
# # hence greater delivered energy.
# #
# # Keith Whaley - pistolsmith
# # WHALEY's Gunsmithing
# # Los Angeles, CA
# #
# #
# # MTNMANN wrote:
# # #
# # # Perhaps this person was using submachine gun ammo which is
# # # supposed to be a bit hotter than pistol ammo.
# # #
# # # Just a thought, not a fact.
# # #
# # # Mtnmann
David Rackley
From: "FBC3" <fb...@aol.com>
# #since a squib load would fail to eject.
#
# Is this for sure? Could a weak load have enough pressure to function the
# action while sticking a bullet in the barrel?
No not for sure. I once had a stuck bullet, but the brass ejected. I
suspect a bad primer or blocked flash hole as the bullet was lodged just
inside the barrel with poorly burnt powder everywhere. The clues were that
the shell ejected at a strange angle and the next round impacted the stuck
bullet and didn't let the receiver go fully into battery. The recoil was
also very weak to non-existent.
Dave
AirborneRanger
# hit the 50 yard berm.
# --
# --henry schaffer
I have no idea if this is possible, but let me ask you this...
If you had continued to lighten the load until a bullet did NOT exit the barrel
could the following happen?
1. The firing sequence starts out normally (gas expanding, bullet forced down
the barrel)
2. The propellant (expanding gas) runs out of juice, and the bullet lodges in
the bore. At this time a typical squib.
Here's where it gets interesting...
3. Even though the bullet has stopped the gas is still expanding, i.e. increasing
it's volume, while the volume of the bore is now constant. This causes a
pressure spike strong enough to cycle the action, but not large enough to
overcome friction and dislodge the bullet.
End result: the action cycles with a squib.
Or...
4. Same as #3 except a pulse wave is sent back toward the action (versus
an overall spike in pressure) cycling the action. This would be the same
as a "water hammer" created in a fire engine when the nozzle man slams the
nozzle shut to quickly, breaking the impeller(s). The medium is different, but
the principle is the same.
Ok physics geeks.....shoot me down ;-)
T.
Clark Magnuson
Marek Stanek wrote:
#
# With 9mm Luger that's right, but not with 7.62x25 TT. The sub-gun load
# is significantly hotter and loaded with heavier steel-core bullet. The
# difference is about 200 Joule of muzzle energy, boosting it up to more
# than 900 Joule. The chamber pressures are also more than 30% higher,
# exceeding even tormentation pressures for pistols.
# I can dig out the ballistic data when I come home, if you wish.
# Mark
What is "tormentation pressures for pistols"?
Clark Magnuson
FBC3 wrote:
#
# #since a squib load would fail to eject.
#
# Is this for sure? Could a weak load have enough pressure to function the
# action while sticking a bullet in the barrel?
That could happen in a blow back, but not a locked breech like a CZ52.
The pressure moves the slide in a blow back, the reaction to the bullet
momentum moves the slide in a locked breech.
P. Roza
#
#
# Marek Stanek wrote:
# #
# # With 9mm Luger that's right, but not with 7.62x25 TT. The sub-gun load
# # difference is about 200 Joule of muzzle energy, boosting it up to more
# # than 900 Joule. The chamber pressures are also more than 30% higher,
# # exceeding even tormentation pressures for pistols.
# # I can dig out the ballistic data when I come home, if you wish.
# # Mark
#
# And who makes that ammunition, Mark? County and manufacturer? Even
# headstamp stamps would be very much appreciated.
#
# Thanks, keith whaley
I have some of the czech subgun ammo. It can be described as follows:
Caliber 7.62x25, Berdin primed, corrosive, brass case, copper-plated, steel
jacketed, lead core, 84.2gr fmj, w/ black primer sealer around edge of
bright yellow brass primer. 10.0gr of unknown flake powder, which fills to
base of neck. 1953 Czech manufacture. The headstamp, in common fashion,
has markings at 12, 4, and 8 O' clock positions. "bxn", "1" (vertical line
only) and "53"
Actual measured velocity from CZ52 pistol was 1555 fps, with a large amount
of unburned powder producing large, amber muzzle flash.
Package consists of stapled, creme colored, cardboard box with a paper
label forming the seal. Label is marked: (ignore placeholding underscores)
" ______________________________139/53 - bxn"
"7,62 - Pi_________________________________"
"___________________________________VIII-53"
"_______________________________________"
"topl/Ms pásk_____________________________"
"_______________________________________"
"40 ks________Ncdp P1 nma 11/53______0,67 g"
Inside are 40 rounds, packaged on 5, 8 round stripper clips, designed for
use with the Czech CZ24 or 26 submachinegun.
It appears to recoil about the same as other standard loadings, and much
less than my hot handloads. I have encountered some ammo, of 1952 Czech S&B
manufacture, packaged 16rds to a box, that was extremely hot, and had
velocity readings over 1800 fps from my cz52, with heavy recoil, which gave
the impression that the slide would jump off the end of its track. This
latter ammo left a strong cordite type stench in the air, and was extremely
corrosive.
KYRIEELLIS
I don't doubt the higher muzzle velocity, as the longer barrels of
sub-machineguns do produce higher muzzle velocities than do shorter pistol
barrels.
However I do have to respectfully question your assertion regarding the
higher chamber pressure (and even the existence) of such sub-machinegun
ammunition. A sub-machinegun is, by definition, a fully automatic weapon that
fires a pistol cartridge. If the Czech army has higher pressure ammunition for
sole use in its sub-machineguns they are unique among the world's armies.
While there does exist ammunition intended primarily for use in
sub-machineguns, this ammunition is loaded to normal pressures and differs from
standard pistol ammunition only in having special purpose (explosive, armor
piercing, tracer, incendiary, etc.) bullets. There is no mechanical reason such
ammunition cannot be fired normally in a service pistol, and it sometimes is.
During WWII, Korea, and Viet-Nam tracer .45 ACP ammunition primarily intended
for use in the M3 sub-machinegun was used quite often in 1911A1 pistols for
signaling.
Best regards,
Kyrie
In article <ag05kl$gqb$1...@grapevine.wam.umd.edu>, "Marek Stanek"
<sta...@post.cz> writes:
#With 9mm Luger that's right, but not with 7.62x25 TT. The sub-gun load
#is significantly hotter and loaded with heavier steel-core bullet. The
#difference is about 200 Joule of muzzle energy, boosting it up to more
#than 900 Joule. The chamber pressures are also more than 30% higher,
#exceeding even tormentation pressures for pistols.
#I can dig out the ballistic data when I come home, if you wish.
#Mark
Moderator - Cruffler_Forum on Yahoo Groups
"The flame free C&R Forum."
http://groups.yahoo.com/group/Cruffler_Forum
Bill
http://www.geocities.com/Yosemite/Gorge/4653/bad.htm
> ...
Marek Stanek
news:ag1b9f$o2v$1...@grapevine.wam.umd.edu...
#
#
# Marek Stanek wrote:
# #
# # With 9mm Luger that's right, but not with 7.62x25 TT. The sub-gun
load
The
# # difference is about 200 Joule of muzzle energy, boosting it up to
more
# # than 900 Joule. The chamber pressures are also more than 30%
higher,
# # exceeding even tormentation pressures for pistols.
# # I can dig out the ballistic data when I come home, if you wish.
# # Mark
#
# What is "tormentation pressures for pistols"?
The english term may be "fire proof"? It's CIP nominal pressure +30%.
Any handgun must withstand 2 rounds fired to be proof-stamped to be
safe for use.
Mark
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Noah...@webtv.net
sounded "funny".
A bullet was stuck in the barrel, but the brass ejected.
The case of the ejected brass was split.
I'm glad that it was not set on full auto.
Marek Stanek
news:ag4176$h1h$1...@grapevine.wam.umd.edu...
#
# "Keith Whaley" <kei...@dslextreme.com> wrote in message
# news:ag1a62$nrc$1...@grapevine.wam.umd.edu...
# "topl/Ms pásk_____________________________"
It should be TbPl - Tombak Plated. Tombak is an alloy of copper and
nickel with high percentage of copper (about 80%).
Mark
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Marek Stanek
news:ag1b6m$o1t$1...@grapevine.wam.umd.edu...
# # But in all of the experiments the bullet went out of the barrel
and
# # hit the 50 yard berm.
# # --
# # --henry schaffer
#
# I have no idea if this is possible, but let me ask you this...
#
# If you had continued to lighten the load until a bullet did NOT exit
the barrel
# could the following happen?
# 1. The firing sequence starts out normally (gas expanding, bullet
forced down
# the barrel)
# 2. The propellant (expanding gas) runs out of juice, and the bullet
lodges in
# the bore. At this time a typical squib.
# Here's where it gets interesting...
# 3. Even though the bullet has stopped the gas is still expanding,
i.e. increasing
# it's volume, while the volume of the bore is now constant. This
causes a
# pressure spike strong enough to cycle the action, but not large
enough to
# overcome friction and dislodge the bullet.
# End result: the action cycles with a squib.
Should in no way happen in a locked-action gun. Can happen with
blowback and semi-locked / delayed-open action as they can be opened /
cycled by pressure in the chamber. Locked action can only be opened /
cycled by recoil, which should not develop with bulled getting stuck
in the barrel (energy preservation law).
Mark
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-----------------------------------------------------------
Marek Stanek
#
#
# Marek Stanek wrote:
# #
# # With 9mm Luger that's right, but not with 7.62x25 TT. The sub-gun
load
The
# # difference is about 200 Joule of muzzle energy, boosting it up to
more
# # than 900 Joule. The chamber pressures are also more than 30%
higher,
# # exceeding even tormentation pressures for pistols.
# # I can dig out the ballistic data when I come home, if you wish.
# # Mark
#
# And who makes that ammunition, Mark? County and manufacturer? Even
# headstamp stamps would be very much appreciated.
Sellier & Bellot produced huge amounts of them for the Czech Army
during 1950's ~ 1980's. Until 1995 they could be obtained as surplus
ammo although they were officially banned for civilians. Someone just
fuc*ed up when surplus ammo was sent to the distribution.
While nothing mostly happened when firing these through CZ-52's, it's
a bad day for cops who still can run up against criminals armed with
them, as the police bulletproof vests are no more bulletproof then.
There have been several cases when police were shot with these through
their vests. AFAIK they all were fatal.
Mark
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Rick McMullen
# blowback and semi-locked / delayed-open action as they can be opened /
# cycled by pressure in the chamber. Locked action can only be opened /
# cycled by recoil, which should not develop with bulled getting stuck
# in the barrel (energy preservation law).
Isn't the CZ-52 a roller-delayed, semi-locked action a la the HK P9S?
I have never handled one, but I seem to recall reading this.
--
Rick McMullen
AirborneRanger
T.
"Marek Stanek" <sta...@post.cz> wrote in message news:ag6m8o$b6q$1...@grapevine.wam.umd.edu...
> ...
FBC3
P38:
"While super loads intended primarily for submachine guns will function
perfectly as a rule, standard brass case pistol types are preferable."
Paul Saccani
On Sat, 6 Jul 2002 11:59:49 +0000 (UTC), kyrie...@aol.com
(KYRIEELLIS) wrote:
# However I do have to respectfully question your assertion regarding the
#higher chamber pressure (and even the existence) of such sub-machinegun
#ammunition. A sub-machinegun is, by definition, a fully automatic weapon that
#fires a pistol cartridge. If the Czech army has higher pressure ammunition for
#sole use in its sub-machineguns they are unique among the world's armies.
We used to have a high pressure load for the 9mm F1 SMG, with a light
rifle primer as well (rifle primers are not uncommon in ammunition
specifically for SMG use). This was discontinued after an accident
with a Browning pistol using that ammunition. The metal ammunition
cases were stencilled "HIGH PRESSURE 9MM, SMG USE ONLY". IIRC, head
stamp was HP, as opposed to HPT, which is still being made.
# While there does exist ammunition intended primarily for use in
#sub-machineguns, this ammunition is loaded to normal pressures and differs from
#standard pistol ammunition only in having special purpose (explosive, armor
#piercing, tracer, incendiary, etc.) bullets. There is no mechanical reason such
#ammunition cannot be fired normally in a service pistol, and it sometimes is.
I would dare say the reason for most armies using standard pressures
is the difficulty in sequestering ammunition so as to prevent
accidents from it being used in pistols unsuitable for it.
cheers,
Paul Saccani
Perth West Australia
Clark Magnuson
#
# from Small Arms of the World, seventh edition, page 400, regarding the Walther
# P38:
#
# "While super loads intended primarily for submachine guns will function
# perfectly as a rule, standard brass case pistol types are preferable."
By the 12th edition in 1983 that passage was dropped from the P38
section. Neither does it appear in the ammo section in the back.
However in another Ezell book, "Handguns of the World [1870-1945]" 1981,
in the ammo section he says, ""A DWM-developed 9mm Luger carbine
cartridge can be identified by its blackened cartridge case and
head-stamp code 480D. Because this cartridge develops a high pressure
that could damage a pistol or injure the shooter, its use should be
restricted to weapons for which was designed.
My hunch is that Ezell either inferred the warning or repeated it from
an untraceable source [urban legend]. I have spent hundred of hours
testing the limits of 9x19mm is various pistols. My interpretation is
that amount of safety margin is so substantial that law suit shy large
corporations are selling 9mm +P+ factory ammo.
Like Kyrie said...
Marek Stanek
news:ag93h4$2ck$1...@grapevine.wam.umd.edu...
# In <ag6m8o$b6q$1...@grapevine.wam.umd.edu>, Marek Stanek wrote:
# #
# # Should in no way happen in a locked-action gun. Can happen with
opened /
# # cycled by pressure in the chamber. Locked action can only be
opened /
# # cycled by recoil, which should not develop with bulled getting
stuck
# # in the barrel (energy preservation law).
#
# Isn't the CZ-52 a roller-delayed, semi-locked action a la the HK
P9S?
# I have never handled one, but I seem to recall reading this.
Right, but it was inspired by MG43 (might be MG42, I just can't
remember which one was which :-) )
Mark
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Clark Magnuson
# Right, but it was inspired by MG43 (might be MG42, I just can't
# remember which one was which :-) )
# Mark
When the CZ52 barrel splits, the roller blocks fall out.
The action may be strong in locking the rearward motion of the slide and
barrel, but the barrel easily splits. And you can't just buy a new
barrel, because the slide splits as a secondary failure.
Samuel W. Heywood
# Hi Marek,
#
# I don't doubt the higher muzzle velocity, as the longer barrels of
# sub-machineguns do produce higher muzzle velocities than do shorter pistol
# barrels.
#
# However I do have to respectfully question your assertion regarding the
# higher chamber pressure (and even the existence) of such sub-machinegun
# ammunition. A sub-machinegun is, by definition, a fully automatic weapon that
# fires a pistol cartridge. If the Czech army has higher pressure ammunition for
# sole use in its sub-machineguns they are unique among the world's armies.
The Czech Army does have higher pressure ammo in 7.62 X 25mm Tokarev
caliber designed primarily for use in its submachine guns. It may be
fired safely in the CZ-52 pistol also. When fired in the pistol the
use of a heavier recoil spring is recommended. The heavier recoil
springs are supplied in the standard issue armorer's kit. The heavy
duty recoil springs may be ordered from http://www.makarov.com and
possibly from some other web sites.
The Czech sub-machine gun ammo may not be safely fired in the Tokarev
pistol, but it is OK to fire it in the CZ-52 pistol.
BTW, there is a very bad lot of defective surplus ammo in 7.62 X 25mm
Tokarev caliber on the market that you need to watch out for. It
is called "Bad Bulgarian". It is of Bulgarian manufacture and the
headstamp bears a number of "53" indicating the year of manufacture.
This ammo is known to produce unacceptably high chamber pressures and
it has been known to cause CZ-52 pistols to explode.
Sam Heywood
-- Message sent by Unix Pine, Version 4.44
Clark Magnuson
"Samuel W. Heywood" wrote:
# The Czech sub-machine gun ammo may not be safely fired in the Tokarev
# pistol, but it is OK to fire it in the CZ-52 pistol.
It might seem reasonable to infer this from the book "Accurate Arms Load
Book Number Two" 2000, but it is still wrong.
In writing that part of the load book, Ted Curtis borrowed a CZ52 for
velocity tests, and the pressure tests on Tokarev ammo from around the
world were done on one of Accurate's standard test guns. Ted neither did
calculation nor tests on the strength of a CZ52 vs a Tokarev. I have. I
have blown up a couple of CZ52s, and have been unable to blow up any
Tokarevs. I have calculated the barrel hoop stress in both.
Of many possible failures, I am interested in this because of the CZ52's
vulnerability to this failure.
How to tell which can handle more pressure: CZ52 or Tokarev:
Measure the OD of the barrel in a CZ52 at the chamber:.590"
Measure the OD of the barrel in a Tokarev at the chamber:.640"
Measure the OD of the barrel in a CZ52 on the barrel:.468"
Measure the OD of the barrel in a Tokarev on the barrel:.494"
The Chamber ID is .390" and the grooves ID is .308" for the 7.62x25mm
Tokarev cartridge.
This makes the walls in the chamber of a CZ52 .1" thick
This makes the walls in the chamber of a Tokarev .125" thick
This makes the walls in the barrel of a CZ52 .08" thick
This makes the walls in the barrel of a Tokarev .093" thick
The formula for thin wall hoop stress is S=[chamber
Pressure][ID]/2[thickness of walls]
Assume 4140 steel heat treated.
If heat commercially treated and quenched 4140 steel has an ultimate
maximum tension yield strength of 180ksi,
http://et.nmsu.edu/~etti/winter99/manufacturing/kollmer/kollmer.html
Then the max chamber pressure for a CZ52 may be calculated:
Pmax[CZ52]ch = S[2][thickness or walls]/[ID]= 180ksi
[2][.1"]/.390"=92,000 psi
Pmax[Tok]ch= 180ksi[2][.125"]/.39"= 115,000 psi
This must be added to the pressure capacity of the brass:
Pbrass = S[2][thickness or walls]/[ID]= 66ksi [2][.035]/[.39
-(2).035]=14kpsi
The CZ52 chamber would then fail at 106,000 psi
The Tokarev chamber would then fail at 129,000 psi
Pmax[CZ52]barrel= S[2][thickness or walls]/[ID]=
180ksi[2][.08"]/.308"=94kpsi
Pmax[Tok]barrel= S[2][thickness or walls]/[ID]= 180ksi[2][.093"]/.308"=
109kpsi
It looks like the barrels are weaker than the chambers.
It looks like the CZ52s are weaker than the Tokarevs.
The 42,000 cup in a CZ52 has 14% safety margin by my experiments.
11.7 gr AA#9 makes a 110 gr FMJ bullet go 1688 fps in a CZ52 "Accurate
load book #2" 42,000 cup.
13.7 gr AA#9 and a 110 gr FMJ bullet will blow up a CZ52 barrel and take
the slide with it.
15.3 gr AA#9 and 110 gr FMJ bullet will make the primer fall out in a
Tokarev.
I have since realized that the AA#9 high bulk modulus
[incompressibility] caused some bullets to push into the lands of the
CZ52 barrels, causing a stuck bullet pressure spike. The Tokarevs have
much more free bore and do not have that problem.
In the future I plan to retest the CZ52 vs Tokarev vs C96.
#From my initial look at the broom handle chamber walls, I expect it to
withstand higher pressure than the CZ52.
Next time I will use AA#5, which should reach very high pressures with
partially filled chambers.
Samuel W. Heywood
#
#
# "Samuel W. Heywood" wrote:
#
# # The Czech sub-machine gun ammo may not be safely fired in the Tokarev
# # pistol, but it is OK to fire it in the CZ-52 pistol.
<snip>
I find your post a most interesting rebuttal to my statement implying
that the CZ-52 can withstand greater pressures than the Tokarev pistol.
What I have said above in my post is just the common information that
I get from gun dealers and ammunition vendors at gun shows. All whom
I have discussed the subject with have warned me about firing the
machine gun ammo in the Tokarev and they say it is OK to fire it in
the CZ-52.
BTW, I know a handloader in my area who says that he has developed
some very hot loads for the CZ-52 which fire 89 grain bullets at
velocities that he has chronographed at 1950 fps. So far he has
not blown up a CZ-52. He uses the heavy duty recoil spring when
firing his hot loads. If he keeps working up his handloads any hotter
than that he might soon find out the truth about how strong the CZ-52
is!
Thanks for the info!
Sam Heywood
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Clark Magnuson
"Samuel W. Heywood" wrote:
# What I have said above in my post is just the common information that
# I get from gun dealers and ammunition vendors at gun shows. All whom
# I have discussed the subject with have warned me about firing the
# machine gun ammo in the Tokarev and they say it is OK to fire it in
# the CZ-52.
The gun culture suffers from urban legends that can be traced to books.
Other gun books pick up the errors and repeat them.
The errors are difficult to dislodge:
1) CZ52s can take hotter loads than a Tokarev.
2) Enfield 303 brass life is due to a springy action.
3) 38 Specials should not be fed a steady diet of +P.
4) Sporterized Mausers should have the bolt faced and re- heat treated.
Just because I know what book and author started the legend, that does
not mean I can wipe it out.