1957 metalurgy change question

[mbliss57]

The question or answer that I have been looking for is the metallurgical history of the S&W steel frame revolver. I am an engineer and work with a pile of super alloy metallurgists.. (Big deal right?) Well it only means that I know that S&W has a documented metallurgical history of changes to their guns. I have no idea what they are or if they are even public knowledge. I assume they have proprietary alloy formulas as well as Heat Treating cycles /temperatures they don't share with Ruger or us.
If they haven't change their metallurgy formulations or heat treating since the 1920s or 1930s on a steel revolver then the +P they put on their barrels could be put on any barrel up until their last metallurgical change. Way back to 1920's. Alloy frames, Sc and Ti cylinders are different. But the run of the mill Model 10 that hasn't changed since pre war times can shoot +P IF there have been no changes made to the metal treatment. This has been said...I said it with a question not an answer as I am not sure this is so. I would ask a S&W metallurgical engineer to be sure it was. My gut says it is..but..

 

[DWalt]

If anyone is interested, the SAAMI.org website contains all ammunition pressure and velocity standards, and much more besides, such as chamber and cartridge dimensions.

The SAAMI specs for .38 Special (158 grain) .38 Special +P (158 grain) and .357 Magnum (158 grain) are provided below. However, the SAAMI specs cover other bullet weights as well.

357 Magnum: Maximum Average Chamber Pressure (MAP) = 35,000 PSI; 15' Velocity with 4" standard vented test bbl = 1220 ft/sec

.38 Special: MAP = 17,000 PSI; 15' Velocity with 4" standard vented test bbl = 750 ft/sec

.38 Special +P: MAP = 20,000 PSI; 15' Velocity with 4" standard vented test bbl = 1050 ft/sec

Note that these are only standards. Actual production MAP values of ammunition from manufacturers may be below these standards. And of course velocities can vary widely depending upon the specific gun and its barrel length. Note that the SAAMI MAP for .38 Special +P is only 3,000 PSI greater than the normal .38 Special - certainly no big deal. It's nothing like the MAP difference of over 100% (18,000 PSI) between .38 Special and .357 Magnum.

By the way - there are no SAAMI MAP specs for +P+. That's up to the ammunition manufacturer to decide for itself.

 

[Hondo44]

The only other references on S&W cyl treatment that I've seen stated by Roy Jinks is that the 357 N frames used "a different type of steel for the frame, barrel and cyl" which would preclude me from ever lengthening a 38 Spl cyl to shoot 357.

And in reference to 44 mag, with cylinders "specially heat treated 4 (or 5) prototype 44 1950 Targets" were used for testing. Presumably the special heat treating carried over into production.

Lastly, regarding the Model 19, again during development "S&W tested various steels and heat treatment processes" pre production.

 

[DWalt]

I can add that there can big a large difference in the Rockwell hardness between post war Heavy Duty cylinders. I used to assume all lost wars bored to accept .357 would be ok. When they actually very a great deal in strength.

Emory

Hardness is very closely correlated to tensile strength. I have never found any actual hardness measurements for different cylinders (e.g., Model 10 vs. Model 19) but I would sure like to find some. That would allow some actual hoop strength calculations to be made. I've made postings in the past asking for anyone with such data to come forward, but it has not happened yet. Surely someone must have access to a Rockwell hardness tester. At one time I did, but that was long ago.

 

[inventorguy]

Heat treatment

Maybe I missed it, but I saw no reference to forcing cones in the above. In my observations, with high pressure loads in a K frame, the first place to expect a failure is the short section of the barrel right in front of the cylinder. If the pressure and bullet construction combine to exceed the strength of this portion of the barrel, the forcing cone will split.(the forcing cone is the conical section of the entrance to the barrel from the chamber of the cylinder) This appears to happen most often with soft lead bullets ahead of heavy powder charges. Possibly the soft lead bullets upset more easily than a jacketed bullet and cause higher pressures as the bullet is being squashed down again so that it can continue through the barrel. I have never seen a .357 N frame forcing cone split. They are much larger in diameter.

 

[Hondo44]

True, and cracked forcing cones have been experienced on the Model 19 even though it's barrel and frame joint was designed beefier than the standard K frames at that junction. The weak point is the flat bottom side of the barrel forcing cone and a major issue that led to the development of the L frame.

 

[Doug M.]

I am sometimes guilty of sarcasm, so I cannot be too critical of those who display it. I am not swift enough about some of the arcana so knowledgeably discussed here to be really sarcastic or facetious the way some can. I can also be a bigger jerk than SP, but try to conceal it.

 

[Texas Star]

Am I the only one here who's read Chic Gaylord's, Handgunner's Guide, printed about 1960?

In it, where he discussed the then fairly new M-10 with heavy barrel, he said that a factory rep had assured him that the gun was made of a new and stronger steel.

I'm sure that other M&P/Model 10 variants were also made of that steel, which I have read elsewhere (wish I could recall where) was an outgrowth of what S & W had learned about steel when developing the Model 19. They needed new data to produce a K-frame gun that'd be safe with .357 pressures.

This DOES NOT mean that M-10 steels are the same as those chosen for the M-19. It does probably mean that about 1957, the firm began using a steel stronger than that previously seen on their .38 Specials.

 

[Hondo44]

And certainly the Model 13 got the same treatment. It probably facilitates production to just use the same Model 19 steel for all 38s (or all revolvers) than have two that are different.

 

[DWalt]

To simplify inventory, logistics, and operations, it would be typical for a manufacturer to standardize the steel alloy and heat treatment methods to the maximum extent possible, e.g., use the same alloy and heat treatment for the Model 10 and the Model 19 frames and cylinders. Whether it actually is or was done that way by S&W I would have no idea.

 

[Alk8944]

To simplify inventory, logistics, and operations, it would be typical for a manufacturer to standardize the steel alloy and heat treatment methods to the maximum extent possible, e.g., use the same alloy and heat treatment for the Model 10 and the Model 19 frames and cylinders. Whether it actually is or was done that way by S&W I would have no idea.

In 1974 while armorer for my department I was sent to the S&W factory for the S&W Armorers School. At the time the school was only for revolvers and my department was one of the early departments to use the Model 39. As a result my school consisted of working in Automatic Production, directly under the then Automatic Foreman Eddie Mitchell, and his Lead Man who's name I can no longer recall. I and the Lead Man performed repairs on all guns that had gone to test-fire and had not passed for some reason. Overall a very interesting experience.

This was, as I recall, before the +P question was much of an issue. My interest was due to handloading and commonly published loads which demonstrated significantly higher performance than factory ammunition then available. I reasoned as has Dwalt that it didn't make sense to use two different steels, and heat treat to different strength levels, when the same parts could be potentially used to build either a Model 14 or 19. So, I used this opportunity to ask a question which would not likely be answered candidly if asked of someone in customer service.

I wish I could recall who I asked this question, but it may have been Mr. Mitchell. You have to understand that at that time at least a department foreman at S&W held a position equivalent to a Vice President in many industries. He would be privy to engineering data from any department.

Now, the question. Somewhat paraphrased after 39 years, and obviously in the context of then current production. What I asked was "Is there any difference in either material or heat treatment between the .38 caliber K-frame guns and the Model 19?" After some hesitation, as this was obviously proprietary information and not for public distribution, he finally said "No, there is no difference." I went on to ask for clarification by asking "Then the Model10 and Model 19 have equal strength?", to which the response was that this was correct. Take this however you want.

There is another myth about the Model 19, and that is that the frame was someway strengthened. This is not true. There is a minor difference in the profile of the front edge of the Model 19 frame, but it is purely cosmetic. The face was extended down slightly and the contour from that surface to front of the yoke for the simple purpose of making the frame mate properly with the extractor shroud of the Model 19, and nothing else. For some reason many believe, erroneously, that because the contour was changed it was for strength. As stated, it was purely cosmetic.

 

[lebomm]

Looks like I stirred up a hornets' nest !
Folks, I never meant to mislead, insult, disrespect or otherwise denigrate anybody ! It was intended as a light moment (that's NOT to imply that this thread is too grave) and I apologize for any ill feeling it may have inculcated.
I respect and admire the members of this forum, that's why I keep coming back here every day.
Again, apologies for any hurt feelings.

Larry

 

[gaucho1]

Looks like I stirred up a hornets' nest !
Folks, I never meant to mislead, insult, disrespect or otherwise denigrate anybody ! It was intended as a light moment (that's NOT to imply that this thread is too grave) and I apologize for any ill feeling it may have inculcated.
I respect and admire the members of this forum, that's why I keep coming back here every day.
Again, apologies for any hurt feelings.

Larry

Please don't sweat it Larry.

This is very old and well trod ground.

Nobody has been petted in the wrong direction so far. Just strongly held
opinions backed up by more or less real info.

Very similar to the what caliber is more effective debate from the beginning
of the known universe.

Enjoy

John

 

[Hondo44]

There is another myth about the Model 19, and that is that the frame was someway strengthened. This is not true. There is a minor difference in the profile of the front edge of the Model 19 frame, but it is purely cosmetic. The face was extended down slightly and the contour from that surface to front of the yoke for the simple purpose of making the frame mate properly with the extractor shroud of the Model 19, and nothing else. For some reason many believe, erroneously, that because the contour was changed it was for strength. As stated, it was purely cosmetic.

I agree it was cosmetic. The "myth" no doubt stems from statements by Roy Jinks in his books.