Given the ctgs of the day it's hard to imagine S&W revolvers having catastrophic failures. Something had to prompt them to add a manufacturing step. It's not like S&W was using junk steel or cast cylinders like the cheap imports. Given the numbers of non-heat treated guns that are still firing factory ctgs successfully after almost 100 years, it's hard to believe it was just the switch to smokeless powder.

Anyone know?

Thoughtful question and a great post! It'd be nice to discover original factory documentation regarding the subject of improved heat treat methods.

It could have had to do with better wear characteristics rather than strength. Or, perhaps it was for strength and providing an extra margin for early 20th century handloaders playing with the comparatively new smokeless powders.

You know how handloaders are...

I thought about the wear angle but isn't most of the potential wear actually on the extractor star? Maybe it was just an honest effort to use best manufacturing processes. As better technology became available S&W decided to adopt it. We're pretty cynical about such things today but maybe then things were different.

The cylinder stop notches are a very common wear point. It might be that they decided to change the heat treatment to eliminate a different problem, not to strengthen the cylinder for handloaders to increase their charges.

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Dick Burg

That makes as much sense as anything rburg.

If I'm starting to make sense to you..... its time for a psych evaluation!

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Dick Burg

I believe that S&W started heat treating cylinders in the early 1900's after the invention of the .357 magnums. I believe that it was felt necessary to contain the excessive pressure created by this new round. S&W also uses different levels of heat treating depending on the caliber. According to Roy Jinks, the .44 magnums get a different heat treating than a .44 special.

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James Redfield
LM #497

I think Dick hit it- the cyl stop notches. Don't forget that S&W had inserted hardened shims beside the notches before heat treating. Heat treating did away with that necessity. So, we had as good a product with far fewer processes.
I also think it was because of smokeless powder.
Heat treatment predates any thought of the 357 Mag.

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Regards,
Lee Jarrett

Hold your horse`s here! Are you saying that S&W didnt start heat treating until 1935 when the .357 mag came out? Then explain to me why the colt single actions found need to start heat treating around 1900 with a lot less pressures than .357! We are talking 35 years earlier than S&W here!

I did not see it but it came from a reliable friend. The local indoor gun range took in a well worn M&P from the early years I think it was a second change 1905. Since the blue was badly worn and they needed another .38 Special renter it wound up on the rental shelf and digested a lot of commerical reloads for quite a while but one day the cylinder split while firing that commerical reloaded ammo.

I think that it could well be a split cylinder every now and then that caused the the change. In 1909 the cylinder notch shims were eliminated from the double action revolvers and heat treating the cylinders would be a lot cheaper than bringing back the cylinder notch shims.

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Gun Safety is no accident.

Heat treated cylinders pre-dates the .357 Magnum introduction by about 25 years.

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Chris
SWCA #2243 SWHF #292

I knew it was for something like that but I guess it was for smokeless powder or the shim removal change. acute CRS attack

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James Redfield
LM #497

In Smith and Wesson: 1857-1945, Neal and Jinks explain that S&W started using the heat treated "shims" in 1896 (presumably with the introduction of the Hand Ejector, First Model) and that they stopped using them in 1909 "after the hardeness of steel used in their cylinders had increased to a point where they felt they were no longer needed." (p. 249) I read somewhere else (same book? not sure) that there were problems with the blued finishes in the early 20th Century because S&W was starting to use newer steels and they did not react to the bluing processes in exactly the same way.

While I cannot cite any definitive source for this conclusion, my understanding is that S&W changed its heat-treat processes several times over the years. During the early history of S&W, steel was not as consistent as it was during later years (e.g. entering the 20th Century). As steel became more consistent, and high carbon steel became more common, it (presumably) became easier for S&W to harden and temper steel and obtain consistent results.

Quite frankly -- I would be surprised if there was ever any centerfire pistol cylinder they didn't heat-treat in some way.

Heat treating the .38's long preceded the .357 Magnum, which arrived in 1935.

Colt was doing this long before S&W, and also added a hammer block about 1905. S&W took until late 1944 to do that, after a gun discharged on being dropped on a ship's deck.

Although peening of the cylinder notches was probably a factor, I think the primary purpose of heat treating was to add safety.

T-Star

Heat treating is the cheapest part of building a pistol. There is no reason not to do it right. I think it costs something like 60 cents a gun or somesuch
Better heat treating began because smokeless propellent raised pressures considerably. It also changed how that pressure was delivered to the various parts, in partricular the charge holes in the cylinders.

Not exactly T-Star. My 1932 Outdoorsman has a hammer block. I think my 1929 2nd Model has one too. They are affixed to the sideplate and flex in/out with the action. This was later changed to something more familiar to us today.

I also remember reading and seeing pictures, but I can't recall where off hand, of the process of installing the hardened cyclinder stop notch shims. I too believe the decision to harden the steel was a cost and labor saving move by S&W. Once action to replace at least three steps (milling the slot for the shim, setting the shim and knocking off the protrusion before polishing).

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Non illegitimae carborundum

If I remember correctly (always a dangerous thing), S&W started heat treating it's revolver cylinders just a few years after WWI ended - during the early 1920's era. This just happens to coincide with the availability of heat treatable alloy steels introduced by the American steel makers. Prior to this, highly stressed small parts were made of regular carbon steels, and their durability was increased by case hardening.

So, the timing, and the change to heat treated cylinders was all linked to available alloy steels, improvement in strength and durability, and streamlining of manufacturing processes of the period. I believe the invention of electrical induction heat treating was also during this period, further supporting this theory since S&W was one of the first to use this new method.

S&W's first hammer block dates to the intro of the 1905-4th Change in 1915.

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Regards,
Lee Jarrett

Just to stir up the pot....

We need to define heat treating before we all go overboard. As I understand it, the 357s went thru a different process (probably a 2nd heat treatment.) Different parts of the guns were made from different grades of steel, and heat treated to different specifications. The period we're talking about was also marked by huge changes in the quality of the steel and the improved manufacturing process, which included the advances in heat treating.

It would appear there is some confusion as to the level or degree of heat treating, and we're suggesting its a simple process. It was refined dramatically in the 25 or so years between 1909 and 1935. And its continued to grow ever since.

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Dick Burg

I do not remember the exact date S&W started heat treating cylinders, though I know it's been mentioned on this board before. However if it started shortly after WW1 something else may have contributed to it. When I purchased my first 1917 I was showing it to some old timers at the local gun shop who had shot pistol competition in the 40's and 50's. They warned me to be cautious when reloading for it because the WW1 production guns had "soft" cylinders. They explained that the 1917 cylinders had been known to bulge chambers when shooting ball ammo in the quantities a competitor would expect to fire.

I suspect a 1917 has about the thinnest cylinder walls of any production S&W from that era. Maybe these guys were repeating an old wives tale,, or maybe they were describing something they had experienced. I do not know but I suspect that if there was going to be trouble with cylinder walls, the 1917 wold be a good candidate.

Is there a particular K-frame serial number range at which we can say for sure a cylinder is heat treated?

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WWSSD?
What would Skeeter do?

I was told once that 22/32's were heat treated beginning in 1925, and shooting ones built prior to that date you shouldn't use High Velocity ammo. Not sure who told me, or if that is actually correct. I do abide by it just because I like to baby my old guns. I've been debating shooting my M&P 1st issue, 1899 with anything other than mild WC target loads. It was shipped in Jan. 1901. I am sure there was some type of heat treatment, just don't know to what level.

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H Richard
SWCA1967 SWHF244

Just came across this thread. Interesting discussion.

Some prewar 38/44 ODs have chambers reamed out to acccept 357s. I am away from my guns so can't eyeball the cylnders, but I would assume the RM cylinders are more robust, can handle higher pressures.... As someone mentioned above, I, too, think the RMs received some sort of extra heat treating, but I s'pose that might be period marketing malarky.

I occasionally consider buying a pre-war Colt Woodsman. Looking into it, I recall that I learned that prior to a certain date, maybe late 1920s mfr, one shouldn't shoot 22 LRs as something --- is it the steel itself? -- is not strong enough or not heat treated or something like that...

"I occasionally consider buying a pre-war Colt Woodsman. Looking into it, I recall that I learned that prior to a certain date, maybe late 1920s mfr, one shouldn't shoot 22 LRs as something --- is it the steel itself? -- is not strong enough or not heat treated or something like that... "

I've read that as well. One shouldn't use high speed Long Rifles in the early Woodsmen pistols.

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John 3:16
WAR EAGLE!

According to Smith & Wesson 1857-1945 by Neal and Jinks, heat treating of cylinders began in 1919 at serial number 316,648 of the 38 Hand Ejector M & P Model 1905 Fourth Change. There is another note in the Engineering Changes section that says that May 7, 1919 was when J.H. Wesson ordered that all 32 Winchester Cylinders were to be heat treated.

Hope this helps.

Steve

Good citation there, Steve. But I think Dick is on to something, too, with what do we mean by heat treating, anyway, as the process evolved over the years, along with metallurgy. E.g., I have read there was a big jump in metalurgical technology during WWII.

I’ve been reading up a bit on the Woodsman. In 1933, Colt went to a hardened mainspring housing and changed the spring to accept high velocity cartridges. Obviously, the old housing couldn’t take the beating. You can easily determine if a Woodsman is safe with HS ammo by looking at the top of the backstrap. Guns with a crosshatched oval should only be used with standard velocity ammunition. Anything else is fine with HS. They change the pattern to horizontal lines when they updated the design. Later series guns don’t have any marking on the backstrap.

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"I also cook."

The early pre-war Woodsmans had a lighter recoil spring and a non-casehardened mainspring housing, which is checkered. Later pre-war guns have lateral grooves in the housing (the upper backstrap area), which indicates it is safe for high-velocity ammo.

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Alan
SWCA LM 2023, SWHF 220

I got in a discussion with a friend about this topic and have searched this and other threads as thoroughly as I can but still don't have a definitive answer, so I'll resurrect the thread... does anyone have a serial number or date that one can use to safely say the cylinder has indeed been hardened (this on a 22/32 in particular.) I've seen such a number in SCSW for the 32-20, but not for the Bekeart Model. They mention that by the time the Kit Gun was developed and catalogued in the mid-thirties, the cylinders were hardened and had recessed chambers, so I know it was earlier than that, and have gotten the impression that the hardening predated the recessed chambers. A little help, please!

Froggie

PS Could a person do a Rockwell Hardness Test on a cylinder and determine whether it had been heat treated to the improved level?

After reading this thread, I wonder if S&W started heat treating because it was a better way to make their guns? We are talking a century ago, when bean counters did not run businesses, the engineers did.

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Always bet on stupidity.

I read somewhere that the 1917 cylinders were heat treated because the government required it. Have no idea about any of the other models.

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Richard Gillespie
FBINA 102

Nightowl, correctamundo! At least according to the SCSW 3rd edition, 1917 section, the government contract for the 1917s stipulated heat treated cylinders. All Smith revolvers soon followed and it was SOP by the early '20s. What the Rockwell hardness specified was is another story. The process evolved and the 357 cylinders of both Colt and Smith underwent a separate and more scientific version and was no doubt improved upon by the time of the 44 Mag.

If 1917 revolver cylinders burst I suspect it was overhardness as requested by the Army. Their track reecord was not good as some may remember the heat treating for the M1903 receivers was also too hard on the 1st million or so. I remember when they were 1st sold as surplus to the public, the American Rifleman warned buyers about not shooting any under # 1,000,000.

That advice turned out to be overkill but it was probably responsible for keeping a ton of early rifles in original military configuration instead of being sporterized and now worth up to $3000.

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Jim
S&WCA #819

It is not so much that a Revolver's Cylinder needs to be 'hard' - it needs to be some amount of hard, but it also needs to be tough.

A 'bulged' Cylinder Wall would suggest the Steel was still ductile or malluable, and who knows if someone put too hot a load through it, or what happened on that. But, better a 'bulge' than flying Shrapnel anyway.

If too 'hard' the Cylinder would shatter 'Like Glass'...so, the question is not exactly about hardness, but overal tensile strength and 'give' resillience or elasticity, meaning in effect 'toughness'.


Terms like 'Heat Treating' tell us nothing since wo do not know the Alloy.

Some Alloys are Air Hardening and will Harden according to their composition with no so called or subsequent 'Heat Treating'.

Other alloys are annealed or made 'soft' be Heating and being allowed to cool at leisure...or, are hardened by Heating and Quenching, where, they then usually require to be 'Tempered' which is done by Heating again but only to a particular Temperature, and, then, quenching.

Everything depends on the Alloy, on the kind of Steel it is, on the properties of the actual Steel in question, and, what is it suited for, or suited to be for once Tempered to a particular point for it's purpose, when appropriate.

The term 'Heat Treating' means nothing or worse than nothing unless we have the rest of the information as for what Alloy or Steel it is.

S&W Could have had Magnum Plus strength Cylinders in the 1880s or 1890s or 1900s by electing an appropriate Steel type and hardening and tempering it appropriately...or, by using one of the early 'High Speed Steels' which tended to be Air Hardening and were not Hardened by Heat or Quenching processes.

So, mentions like the Gov't stipulating that the M1917 Cylinder be 'Heat Treated' is totally ambiguous or meaningless without the rest of the info as for what the Steel or Alloy was, as are those mentions of the 'Heat Treatment' of the K-Frame Cylinders starting in 1920-something.

And, given that I am fairly sure there were so called 'Air Hardening' High Speed Steels of quite a few specific kinds by then ( seeing they existed by the 1880s we know much had been added and improved by WWI ), they could have been making enormously stronger Cylinders with no 'heat treating' whatever...for which, the cost of Tooling to Machine the Cylinders, would have been the Deal Breaker, since the Tungsten Carbide Tooling needed was j-u-s-t barely being developed in Germany in the early '20s...and, Diamond Tooling was a ways away yet.

There is no indication I am aware of to suggest there had been any Cylinder failures in the m1899 or subsequent Models of the M&P or K-Frame Revolvers prior to the early 1920s.

And, by sometime in mid 1899, the .38 Special Cartridge went on to being a Smokeless one, equal to or surpassing the SAAMI Loadings of to-day, so...it is not as if the initial Cartridges for the .38 Special Revolvers were at all any less powerful than those of our present time. And, many people believe they were in fact more powerful than those of to-day.


The 'switch' to Smokelss occurred more or less as the M1899 was being introduced. Cartridge Manufacturers simply made and offered Smokeless and Black Powder Cartridges then, since the Revolvers were good to go with either one.

While the .38 Special Cartridge was originally designed ( in 1898 I think ) to be a Black Powder Cartridge, the change occurred very early ( 1899 ).

As far as I gather, one could none-the-less buy either Black Powder or Smokeless Cartridges in .38 Special, at least till sometime into the mid 1920s.

Original Black Powder performance was listed as being 156 Grain RN Lead Bullet, and, 950 FPS ( but I do not know from what Barrel Length ).

If memory serve, this was with 21.5 Grains of .3F Black Powder, and, 'Folded Head' or 'Baloon Head' Cartridge Cases.

Improvements in Cartridge Cases prevent us from getting more than m-a-y-b-e, about 18 or so Grains of 3F Black Powder into a now-a-days .38 Special Cartridge case, unless we hold the Bullet out farther than usual, and, there is not much for 'farther' to hold it out, without the Bullet protruding from the Cylinder and interfering with the Cylinder's rotation, so...far as that goes...

I myself simply do not understand what is meant in this context by 'Heat Treating' and I do not know what was being done or what Steels or what Alloy was being used prior to so called 'Heat Treating' being introduced...nor once it was introduced.


Again - Alloys capable of standing .357 Pressures, in a K Frame, were long since available anyway, and could have been used in the m1899 right from the get go, and if they had wanted to, they could have introduced the .357 Magnum in 1899 and been fine...so, none of this makes any sense, or none of it makes any sense without the key information as for what Steels were being used, and, why they were being used ( machinability factors in relation to Tensile Strength, in relation to the particular Alloy's requirements for processes of Hardening, being Machined in an annealed condition , in semi hardened conditions, etc, avoidance of High Speed Steels oweing to Maching costs and troubles, distortions occurring if using certain Temperable Alloys if being machined 'soft' and then being 'Hardened', too costly to machine 'Hardened' Steels once Hardened to avoid distortions of post-machinging distortions, etc. Always there are a confluence of Reasons for the Alloy one uses or elects for a partilulat purpose or part, so, who knows? etc ).

I have a 4th. change 6" from June 1919. Serial # 2996xx. I think nothing about shooting sensible loads through it. I load 3, to 3.2 gr Clays w/ a 158gr. LSWC. Don't shoot +P, or 110-125 gr. hot loads through it. Those old M&P's are good shooters in my book. Bob

Some of the older gunsmithing texts from the 1950s provide fairly detailed discussions about metal treatment. The ability to harden steel depends almost exclusively on the alloy used. You actually can't harden some low-carbon steels by heat treatment alone no matter how you try, but there are some methods that can be used to increase surface hardness. There is a fairly good relationship between Rockwell hardness and tensile strength, so yes, one can estimate tensile strength by measuring hardness. Look up (Google) the "Barlow," "Boardman" and "Lame" formulas if you want to know how ultimate tensile strength, diameter, and wall thickness affect rupture pressure of cylinders (such as gun barrels and revolver cylinders)

Yes, 'Case Hardening' allows Wrought Iron or so called 'mild' Steels to have a very Hard layer at their surface.

I do not believe anyone however, had ever offered Case Hardened Cylinders, even if offering Case Hardened Frames and Hammers or other parts.


The average Leaf Spring of any Automobile of the era, was probably not far from, or was on par with, the Steel used in Revolver Cylinders.

Very tough, very strong, but not actually what anyone would call 'Hard'.

If you can get a 'bite' with a new Mill File, then I would not call it 'Hard' Steel.

And, again, "Hard' is not the quality one would want in a Revolver Cylinder - the quality one would want is that of 'Toughness'.

In further brooding on this, I continue to imagine that the real issue of the day, was to elect an Alloy, and, to respect it's Tempering requirements for the job, while still respecting the realities of Machining it with the Tooling of the day...and, to weigh the costs and efforts of these.

Possibly too, there was the desire for the Cylinder to be Blue-able in keeping with the rest of the Revolver, and, this also would have effected the range of available candidate Alloys.

Straight Razors and Scalpels were considered 'Hard', as far as that goes, as regard how 'hard' Hard is, to be considered 'Hard'.

Steel tempered to that Hardness would shatter into shrapnel if used in a Revolver Cylinder, unless it were to have unusually thick walls...but regardless, it would not be a good choice for the job.

Revolver Cylinders, then or now, are not 'Hard' Steel...and, far as I know, they allow a good 'bite' to be had with a new File.

Files traditionally were considered 'Hard' Steel, by way of further comparison.

Drop a good quality File on a Concrete Floor, and, it can break or shatter.