When I destroyed two CZ52 pistols in 2000 with experimental handloaded overloads, and then could not harm Tokarevs with much higher overloads, I found the weak spot, the bottom of the CZ52 chamber was very thin, [.058" CZ52, .125" Tokarev], because the underside had been milled out to make room for the roller blocks. I began to question the premise that the CZ52 is stronger commonly printed in books, magazines, ammo manufacturers etc., though out the gun culture.
http://www.thehighroad.org/attachment.php?s=&postid=249178
This is what I now believe probably happened to get this error into the gun culture:
1) In 1970 the US army published an account of the CZ52 pistol.
Knowing that:
a) The Russians had a TT-33 pistol designed in 1933 that Russian Tokarev ammo loaded to 31 k c.u.p.
b) The Checks had a CZ52 was designed in 1952 and that Czech 7.62x25mm Tokarev ammo was 42 k c.u.p.
c) The CZ52 has a roller block locking system.
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."
2) In March 2000, I got a Letter [as did many others, and the letter was handed out at the shot show] from Ted Curtis ballistician at Accurate Arms. Ted Curtis, a very old ballistician already was bald and had jowls in his 1966 photo in "Speer 7". All the typos are Ted's:
"7.62 X 25 Tokarev ..
Due to the large number of handguns imported into the U.S. chambered
for the 7-62 x 25 Tokarev Accurate Arms has developed the following load
data for those shooters who wish to reload the little powerhouse. In
determining the appropriate pressure limit for our load data we tested
various military ammo from China, Russia, Austria Bulgaria and the
Czech Republic. Commercial ammo produced by Sellier & Bellot was also
tested. Based on these tests we arrived at a maximum pressure for our
lad data of 42,000 C.U.P. Only the single lot of Russian ammo was
significantly below this pressure averaging 31,000 C.U.P. The consistent
pressures between all other type sand manufactures was a welcome
surprise . Indeed, the fact that CZech ammo, made for the CZ-52 pistol,
produced the same pressure as that of the other countries was perhaps
the biggest surprise of the whole project. This in spite of the "tribal
lore" regarding this particular handgun and the ammo loaded for it
claiming that shooting Czech ammo in any other firearm so chambered will
causes spontaneous disassembly. The pressure data produced by the ammo
tested certainly doesn't support this theory.
[Ted presented some loads with AA#2, AA#5, and AA#9 that were at 42 k c.u.p. and very high velocity]
..We feel that the maximum loads shown here are suitable for the CZ-52 so
long as the firearm is in good condition. Other models of foreign
handguns of a lessor quality should probably be loaded in a more
cautious manner. "
3) What I believe happened was that:
a) 1970 the army was not aware or did not realize the implication if China, Poland, and Bulgaria were also producing 42 k c.u.p. Tokarev ammo and it was for their domestically produced Tokarevs. The army's technical writer working on the paper either did not have a CZ52 sample in 1970 or was unwilling to do destructive tests, unwilling or unable to do a mechanical strength analysis, or was distracted by the roller locking mechanism.
b) If Czech ammo for CZ52s is 42 k.c.u.p. and is the same as 42 k c.u.p. ammo China, Austria, Bulgaria, and Poland make for their Tokarevs, the ammo being used does not imply the CZ52 is stronger.
c) When Ted measured the communist block Tokarev ammo, he realized there was an error in the 'tribal lore', but he did not realize that his data implied that the rational [ used infer the CZ52 was stronger than the Tokarev] was gone. He then published his loads for "the CZ52 only".
d) When I notified Sierra [a very good company with a very good rifle handload book] that their "CZ52 is stronger" line in their handgun load book was wrong, I got a typical reaction, ~ "We are impressed with your load data, but we were just printing what WE read."
e) When I notified GUNWORLD magazine that their line, "The CZ52 is stronger" was in error, Jan Libourel wrote me that he was just ~" printing what HE read".
f) When I posted on the internet that "The CZ52 is not stronger" I got many negative reactions from CZ52 owners that missed the nuance between [that CZ52 are not as strong as the Tokarev] and [that CZ52s will blow up with factory ammo].