Brass Expansion in a .357
Mike Janeczko
4" blue (S&W Model 19, I think). Anway, at the range the other day we both
were firing maximum loads. After shooting 6 rounds, the brass smoothly came
out of my cylinder. My friend's rounds didn't come out so smoothly. He had
to bang the ejector on the bench for a couple of minutes before they finally
came out. My question is: does the length of the barrel have somehting to
do with the brass getting stuck or is it the bluing? Anyone have any answers?
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Michael Janeczko | Environmental Research Institute of Michigan
Research Scientist | P.O. Box 134001
internets: | Ann Arbor, MI 48113-4001
jane...@erim.org | Phone: (313) 994-1200 x2676
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"better to be judged by twelve than carried by six."
Frank Crary
#A friend and I both have .357's. I have a 6" stainless(S&W 686) and he has a
#4" blue (S&W Model 19, I think). Anway, at the range the other day we both
#were firing maximum loads. After shooting 6 rounds, the brass smoothly came
#out of my cylinder. My friend's rounds didn't come out so smoothly. He had
#to bang the ejector on the bench for a couple of minutes before they finally
#came out. My question is: does the length of the barrel have somehting to
#do with the brass getting stuck or is it the bluing? Anyone have any answers?
A can't imagine how the bluing versus stainless could have any effect
(if anything I'd expect the reverse: Stainless would have more trouble
than blued carbon steel...) The barrel length might have a slight effect,
since the pressure is sustained for a longer time. However, I suspect
the real cause is maintaince: If your friend has fired .38 from his gun,
there might be some lead build up towards the end of the barrel.
Irregularities, wear, lead build up, general grime, etc... in the chamber
will make extraction more difficult. Your friend probebly just needs to
clean his cylinder very carefully, especially if he's been shooting .38.
Getting and using a .40" brass brush for the cylinder might not be a bad
idea...
Frank Crary
CU Boulder
Gary Coffman
#A friend and I both have .357's. I have a 6" stainless(S&W 686) and he has a
#4" blue (S&W Model 19, I think). Anway, at the range the other day we both
#were firing maximum loads. After shooting 6 rounds, the brass smoothly came
#out of my cylinder. My friend's rounds didn't come out so smoothly. He had
#to bang the ejector on the bench for a couple of minutes before they finally
#came out. My question is: does the length of the barrel have somehting to
#do with the brass getting stuck or is it the bluing? Anyone have any answers?
Barrel length shouldn't matter, but a rough chamber would. Examine the
chambers of his revolver carefully for size and finish. A Mod 19's
chambers are a tad on the thin side for very hot loads. They may be
springing out slightly during firing and gripping the overexpanded
brass too tightly when they spring back. Mike the fired cases to
confirm this.
Gary
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Mark Sechrest
##4" blue (S&W Model 19, I think). Anway, at the range the other day we both
##were firing maximum loads. After shooting 6 rounds, the brass smoothly came
##out of my cylinder. My friend's rounds didn't come out so smoothly. He had
##to bang the ejector on the bench for a couple of minutes before they finally
##came out. My question is: does the length of the barrel have somehting to
##do with the brass getting stuck or is it the bluing? Anyone have any answers?
#
I've had this happen to me when shooting my roommates Dan Wesson .357 with
an 8 in. barrel. We think that the loads we were shooting that day were
hotter than normal. They also tended to stick in another friends 6" S&W.
Possibly higher pressures were being generated and deformed the brass
slightly. That's the best explanation we've been able to come up with.
When we switched to another box of ammo, the shells extracted perfectly.
Mark
John Bercovitz
#A friend and I both have .357's. I have a 6" stainless(S&W 686) and he has a
#4" blue (S&W Model 19, I think). Anway, at the range the other day we both
#were firing maximum loads. After shooting 6 rounds, the brass smoothly came
#out of my cylinder. My friend's rounds didn't come out so smoothly. He had
#to bang the ejector on the bench for a couple of minutes before they finally
#came out. My question is: does the length of the barrel have somehting to
#do with the brass getting stuck or is it the bluing? Anyone have any answers?
This used to be a really well-known phenomenon when there were a lot of
model 19s around. It's real simple - the model 19 is a K frame and has
thin chamber walls. In fact, the wall expands more than the springback
of the cartridge case with a near-max pressure round. So the cartridge
case gets stuck. This won't happen with an L frame or an N frame because
they both have thick chamber walls.
Steel has a spring constant called the "Young's modulus" which governs
how much a given piece of it stretches under a given stress. The strength
of the particular type of steel doesn't matter, this spring constant is
about the same for all types. Even though the type and amount of steel in
the K frame's cylinder is strong enough to take full-pressure 357 loads, it
stretches a lot because it's so thin that the stress is very high. Before the
model 19 came out, manufacturers commonly loaded factory 357 ammo a lot hotter
than they do now. But one caveat here, even though the cylinder will take
hot loads (even if you have to pound 'em out of the chambers), the rest
of the gun will get pretty beat up in very short order. Particularly, the
barrel/cylinder gap will be altered quickly. Whom to blame? Well, it
was Jordan's idea, he pushed S&W into it. But they should have been smart
enough to resist. Colt always built 357s on a frame equivalent to the L frame.
And no, I'm a Smith man, not a Colt man when it comes to revolvers. 8-)
My model 27 (N frame) has had thousands of rounds through it each of which
would jam a K frame. I used to have a super-accurate match load using
Sierra bullets which was near max hence the "thousands of rounds".
The gun has never had any problems as a result of this.
Another thing to watch for on the 19 is locking notch dents in the
chamber. If you raise the pressure high enough, the weakest part of the
cylinder, the part where the exterior locking notch is, gives way a little.
(plastic deformation). Then you'll always have problems with stuck cases.
Best thing to do is send it back to Smith for a new cylinder. You see
this especially with +P+ in K frame 38's. The problem is that the
notch is right in the thinnest part of the chamber in the case of a S&W.
Not shifted off to the side as in so many other revolvers.
John Bercovitz (JHBer...@lbl.gov)
Jim Heath
# A friend and I both have .357's. I have a 6" stainless(S&W 686) and he has a
# 4" blue (S&W Model 19, I think). Anway, at the range the other day we both
# were firing maximum loads. After shooting 6 rounds, the brass smoothly came
# out of my cylinder. My friend's rounds didn't come out so smoothly. He had
# to bang the ejector on the bench for a couple of minutes before they finally
# came out. My question is: does the length of the barrel have somehting to
# do with the brass getting stuck or is it the bluing? Anyone have any answers?
#
I think barrel length has little to do with it. How polished (and clean)
the chambers are has everything to do with it. Was your friend recently
shooting .38 spls? There might be some variance in size of the chambers
as well. I don't think stainless vs. ? (the chambers aren't blued are
they?) makes much difference.
--
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Though all the world betrays thee.
One sword, at least, thy rights shall guard, (The Minstrel Boy)
One faithful harp will praise thee." (Thomas Moore)