The Original CZ Forum
CZ PISTOL CLUBS => CZ82 & CZ83 CLUB => Topic started by: tenfourk on June 04, 2014, 06:27:37 PM
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I finally got to the range with my new(to me) surplus CZ-83. It performed flawlessly with 4 different types of ammo. I noticed however that many of the cases had gotten stained black by what I assume are gases escaping into the chamber before ejection. The blackened area I would estimate covers at worst maybe 25% of the case. Can anyone explain what might be going on from this short description? Is it unusual? I haven't been to the range much and don't remember if this may be more commonplace than I suppose. Are there any safety concerns? I'd appreciate any feedback. Thank you.
Sean
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Did this happen with all four brands of ammo?
I wouldn't worry about any safety concerns as long as the ammo functios fine.
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This happens to my CZ83 a lot if I shoot very light loads. I think that low pressure rounds are not able to fully seal the case against the chamber wall, letting dirty gas escape backwards and blackening the case.
I wouldn't worry about it too much
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Lemming +1
The type of powder used also can contribute to sooty deposits. Some ammo brands will shoot cleaner than others at low pressures.
As said, not a safety concern if the bullet is hitting the target.
E.G>: My light competition light loads leave some sooty residue on the cases and in the pistol, especially with Winchester 231/HP-38 powder. With full power loads there's very little residue.
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Lemming +1
The type of powder used also can contribute to sooty deposits. Some ammo brands will shoot cleaner than others at low pressures.
As said, not a safety concern if the bullet is hitting the target.
E.G>: My light competition light loads leave some sooty residue on the cases and in the pistol, especially with Winchester 231/HP-38 powder. With full power loads there's very little residue.
Yep.
I'm not that familiar with .380 ACP factory loadings. .380 has a maximum average peak pressure of 21,500 psi, as opposed to 35,000 psi for 9mm Luger. I suspect that many manufacturers use the same or similar powders for .380 as they do with 9mm. This would translate into more residue from the powder charge combusting incompletely.
Most handloaders use the same or similar powders for .380 they would with .38 Special +P (18,500 psi). If you compare the case volumes of .38 Special, .380 ACP, and 9mm Luger, you will notice that .38 Special cases are significantly larger (due to the chambering's black powder origins). Commercial manufacturers are not limited to the powders marketed to handloaders. While they could contract for a powder specifically designed for .380, it wouldn't be economical. Since most of the powders used in .38 Special commercial loadings would be too "bulky," I suspect that they are using powders which are too slow-burning for 21,500 psi (i.e. more suited for 9mm, .40 S&W, etc.).
Some of this is speculation on my part, but it is consistent with my limited experience with .380 ACP and U.S-manufactured 9mm Makarov loadings. (Eastern European 9mm Mak loads seem to use powders developed for that chambering/application.)
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Outside case soot is indicative of failure of the case to seal in the chamber. It is caused by: A. oversized chamber; B. harder brass; C. low-powered load; D. the blow-back design of the -82/83 which uses the pressure to literally "push" the casing backwards for ejection; or E. any or all of the above. In general, it's not a concern.
With my low-to-mid-power target reloads, my CZ-82 rounds not only soot, sprinkles of unburned powder will be speckled all over my shirt after a range session.
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With my low-to-mid-power target reloads, my CZ-82 rounds not only soot, sprinkles of unburned powder will be speckled all over my shirt after a range session.
Me too
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Great feedback, thanks guys. Took it out to the range today armed with your feedback and felt a lot better about shooting it. Loving it. When I'm doing my part it is amazingly accurate! And again, it ate everything up without a hiccup. I found the blackening again with all types of ammo.