To say the least, I am very fond of my Smith
& Wesson Model 19 and am interested in prolonging
its life a much as possible while still being able to use it as
intended. So it was with some concern that I read reports that
others had experienced a terrible disaster with their Model 19s:
a cracked barrel throat. I had heard such stories in the past,
but there were never any basis for them, just rumor. I needed to
find out for myself from people who had the facts.
Over the past several months I have been in
pursuit of hard facts that I hoped would put to an end, at least
for me, the question of whether or not a full time diet of
magnum loads would lead to premature failure of the K-Frame
magnum revolvers. I have learned quite a lot and have had the
good fortune to have had input from numerous sources including
police officers, gunsmiths, shooting sports professionals,
sportsmen, and hunters. The
results of this review are discussed in the following
paragraphs.
Was I convinced that the claims of failures were
Old Wives Tales? No.
Was I convinced that one should sparingly use
magnum loads in the K-Frame? No…and Yes.
Will I change the way I use my Model 19? … No.
But… you should read the rest of the article
and judge for yourself.
When the K-Frame magnum was developed it was
intended to provide a lighter weight revolver for the .357
magnum cartridge. As such, it is somewhat of a compromise
between the N-Frame revolver, the Model 27 and earlier .38
Special revolvers. In the beginning, most ammunition was lead
158-grain high-velocity as offered by most manufacturers. There
is a good deal of information that points to the almost
indefinite life of the revolver with reasonable care and a diet
of 158-grain lead bullet magnum ammunition.
As gun enthusiast know, well enough is never
left alone, and the inevitable urge for more power, higher
velocity, and explosive terminal ballistics resulted in
development of a number of jacketed bullets from 110 to 160
grains. These jacketed bullets could be driven to higher and
higher velocities. Based on the “numbers”, they far
out-performed their swaged or cast counterparts. Thus, the first
magnum cartridge evolved rapidly. When introduced, the K-frame
revolvers, due to their many desirable characteristics, became
one of the most popular handguns on the market and sales far
exceeded Smith and Wesson’s expectations.
As a young handgunner, my own load development
efforts pushed the limits of the K-Frame capabilities. Without
sophisticated monitoring equipment, I carefully approached each
load increasing powder charges in small (0.1 grain) increments.
Cautiously changing primers and even cases to detect any
indications of excessive pressure. Primers were my key pressure
indicator. As pressure increased the primer would begin to
flatten out around the primer pocket and then start to flow back
into the firing pin hole. Minute changes in powder charge could
be seen to significantly increase chamber pressure, sometimes
almost exponentially. On a rare occasion, a minor load change
would result in cases sticking in the chamber. THAT’S
DANGEROUS! S&Ws have great chambers and are not prone to
resisting case removal. When a cartridge case sticks, it is a
sign of excessive pressure and significant backing away should
begin immediately. There are those who do not heed the signs and
end up with seriously damaged firearms and possibly injuries.
Back to the question at hand: what should you
shoot in your model 19? From my discussions, review, and the
first hand accounts of many experts in the firearms industry, it
is clear that in the design of the K-Frame revolver some
compromises were made. These changes were made to create an easy
to carry, powerful, accurate, and absolutely most beautiful
handgun ever made. The changes also may have introduced some
generic weaknesses. Most firearms have some generic design
weaknesses. One of the weaknesses in the K-Frame is in the cut
on the bottom of the barrel throat, in the forcing cone area, to
accommodate the cylinder swing. In the attached photo you can
see the flat region on the bottom of the barrel throat.
I’ve been told that when the Model 19-5 was
issued, the production process changed related to the barrel
installation in the frame. Barrels were compression,
“crush-fit”, into the frame. Compression force could
introduce stress and potential latent flaws in the barrel
throat.
Cylinders long enough to accommodate full charge
158 grain bullets provide a great deal of free space when
shorter bullets are used. A very popular loading for the .357
magnum was for the 125 grain jacketed bullet. In the early days,
this was a great combination with high velocities and excellent
terminal performance. Today’s bullet designs offer equal or
better performance from heavier weight bullets and over a
broader range of velocities.
The bearing surface length of the 125 grain bullet is
shorter than the bearing surface of the 158 grain bullet. This
difference means that as the 125 grain bullet leaves the case
there is a gap between the leading edge of the bullet sealing
surface and the cylinder throat. As the short bullet makes this
jump, combustion gases and powder are permitted to blow past the
bullet and prematurely escape into the barrel. The 158 grain
bullet essentially seals off the cylinder as it leaves the case
and enters the cylinder throat. More complete combustion of the
powder is accomplished. Temperatures of the gas as it enters the
barrel are lower and the combustion environment in the barrel is
not oxygen rich as is the case for the prematurely escaping
combustion gas. Checking
the dimensions of my 19-3 confirms that for the 158 grain HP
bullet, the leading edge of the bullet is engaging the lands as
the base of the bullet has just left the case mouth and is flush
with the cylinder throat. For the lighter HP bullets of 115 to
125 grains, there is a gap of approximately 0.15 to 0.12 inch,
respectively.
The problem with the gap of the shorter bullet
is that it permits excessive hot burning gases to escape past
the bullet into barrel throat. This superheats the surface of
the barrel throat with the hot gas plasma. Still unburned powder
blasts away at the barrel throat surfaces and the repeated
impact of the high velocity bullets on the lower surface of the
throat region result in erosion of the throat in this area. One
might question why the impact and erosion is predominantly at
the six o’clock position. Recoil. Longer bullets are guided by
the cylinder throat and thus are not impacting the lower barrel
throat as with shorter bullets. The shorter bullets have a
longer “jump” from the case mouth to the barrel lands and
thus pick up more velocity prior to engaging the rifling. This
causes a greater impact force on the rifling contact area.
Another detrimental effect is the flame cutting of the frame as
these super hot gases escape from the cylinder-barrel gap. This
problem would be present for short bullets in all models of
firearms.
Based
upon reports of those who have seen examples of throat cracks,
several characteristics appear common. First, erosion at the six
o’clock position in the throat is almost always present. Most
describe this as “peening”. Second, the weapons have
generally not been thoroughly cleaned after use. Deposit of lead
and bullet fouling are present in the throat erosion region.
These deposits can create conditions for chemical stress
corrosion and initiation of microscopic cracks in the steel.
Third, most of the weapons have other signs of excessive use and
wear, possibly from overly hot loads. Very small to large cracks
can form at this particular point, the six o’clock position,
in the barrel throat. The impact force of the bullet on the
rifling would increase the probability of a problem in this
region.
Actual
reported data collected during this review is summarized in the
table below.
| Model |
Number of Guns Observed |
Crack Y/N |
158 grain Rounds Fired |
125 grain Rounds Fired |
| 19-5 |
3 |
Y |
100s |
1000s |
| 19-7 |
3 |
Y |
1,500-2,500 |
100-500 |
| 19-4 |
2 |
Y |
2,500-5,000 |
1000 |
| 19-4 |
1 |
Y |
5,000-10,000 (lead only) |
0 |
| 19-4 |
2 |
N |
5,000+ |
<500-1,000 |
| 19-3 |
1 |
Y |
? |
2,500 |
| 19-? |
2 |
Y |
<500 |
150 |
It should be noted that a lot
of weapons never see very heavy use. Initially, I would put 50
to 100 rounds per week through mine. This was during the period
of load and skill development. After that, I probably only shot
250 to 300 rounds per year for the next 3 to 4 years. Once I had
acquired several additional firearms to occupy my mind and time,
my 19 became more of a hunting tool. Currently, I probably fire
about 50 to 100 rounds per year. I conservatively estimate that
my Model 19 has seen a total of 3000 to 4000 rounds. Today it is
as tight and bright as it was the day it was unwrapped.
There are some other
interesting tidbits of information gathered during this review.
This phenomena is not limited to Model 19 revolvers, although
S&W stainless medium frame models may be more resistant to
crack initiation. On rare occasion, cracks have been reported
with fewer than 150 rounds of the 125 grain magnum loads fired.
A few reports of cracks have been made with only 158 grain loads
used. One report was received of a Colt Python that
cracked with the first box of 158 grain magnum shells. Also, I
have even heard of an example where a new unfired revolver was
purchased with a crack in the barrel from manufacturing. Even
the best quality control is not perfect.
Notwithstanding my own
observations, anecdotal data indicates that this crack failure
occurs only rarely. Most people will never see such cracks in a
lifetime of shooting. That’s why there is talk about the
cracking phenomena without much first hand information. Some
shooters fire many thousands of rounds per year. While they may
eventually wear their guns out to the point of requiring parts
replacement, they may never see the cracking. This has been the
case with many of the people contacted during this review.
Others significantly reduce the life of their weapons by what
the feed it and how they care for it. Occasionally a defect will
show up and prematurely fail the weapon.
What’s the bottom line?
Smith and Wesson stands behind their products and when a rare
failure occurs, they make it right. That doesn’t mean that one
should stretch the limits of their weapons and ask them to do
what they were not intended to do.
My Model 19-3 has been a great
weapon and hunting partner for over 30 years. Maybe the
production processes of the earlier models like mine give them
some added resistance to the cracking issue. I will continue to
shoot reasonable magnum loads in it with the full belief and
confidence that it will outlast me. I take care of my Model 19
as one should for any good weapon.
I
hope this discussion will help put this issue in perspective.
Also by providing some factual information, though limited in
numbers of examples, we may provide some insight into the causes
of such failures. Finally, understanding the strengths and
limitations of the very best magnum revolver, the Smith and
Wesson Model 19, will enhance all of our shooting enjoyment and
help preserve examples of this fine firearm for generations to
come.
Butch
Kent
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