I've read a lot of articles and threads on this forum relating to forcing cone issues in the Model 19. Very few (if any) make reference to the Model 66. Is the Model 66 inherently more durable because it's stainless, or about the same as a model 19?

The construction is virtually identical and durability should be the same. The forcing cone issue was more related to high velocity short (125 grain) bullets. Using other types of loads will extend the life of the K frame magnums. When the Model 19 was built it was supposed to be a "peace officer's dream". Lighter than the previous N frame magnums but still able to fire a high power round.

Back then the standard police firearms training doctrine was to fire 148 grain target wadcutter 38 special rounds for practice and qualification and then carry the magnum rounds for duty. It wasn't until the mid 70s that the cops started shooting what they carried on duty. The Federal and Remington 125 grain magnum round was a screamer and very popular. Unfortunately the combination of a shorter bullet and hot powder sometimes caused the cracking issue.

I have a friend that was on the Anchorage PD in the firearms section. They issued Model 13s for a time and he managed to split a few forcing cones but it usually took a lot of the Federal 125 grain magnum rounds. He is immune to the magnum recoil and is not a typical K frame user.

Moral of the story, don't fire a bunch of 125 grain Federal or Remington magnum rounds through your magnum K frame and it will probably outlast you.

The most commonly used steel for blued revolvers is either 4140 or 4340. For stainless steel firearms it's typee 416 stainless. What is interesting is that both the plain steel and stainless alloys of these types have nearly identical heat treat procedures and strength profiles. In mechanical terms they are pretty much interchangeable. Now, I don't know specifically what S&W uses but odds are that it's steels of these types.. Based on that I would expect that the durability of either gun is probably identical.

Excellent feedback!!!

This forum is incredibly educational and informative.

Thanks very much!

While I think the "durability" question as it relates to the hardness and quality of the steels has been answered above, I would add that "durability", at least for me, also involves appearance.

In that regard, my nod ALWAYS went to the 66. I live in the tropics and stainless is a Godsend imo. It too will rust, and it will develop holster wear as well, it just doesn't show as quickly, and is much easier repaired. I've owned beaucoup 66's over the years but never a 19 for this reason. Today I only own stainless guns (lone exception is a just too neat to pass up 27-2 3.5"), from 1911's to S&W's.


Just my .02.

I also consider the durability issue to include finish, and stainless is obviously more durable and easier to maintain than blued.

I personally think the stainless barrel throat resists erosion better, and Winchester used stainless barrels as far back as the 1930's in Model 70 rifles chambered for the .220 Swift cartridge, which had a tendency to erode barrels quickly.

Back in the 1980's one of the gun mags did an article on stainless, and the author said that factory engineers had told him that S&W stainless barrels stood up better. But that might mean primarily that the rifling endured better. I wouldn't run a lot of hot loads with light bullets in either a blue or a stainless K-Magnum.

My M-66-3 was bought new in 1990, and has had maybe 15% .357 loads through it. Based on what S&W personnel told me, I almost never shoot 125 grain or lighter ammo, and stick to the 140-158 grain range. I do have some Remington 165 grain hunting loads on hand, in case I'm ever in bear country with just a .357. The slight weight difference over the 158's doesn't make the difference; the heavier bullet is supposely structured to provide deeper penetration in deer and larger animals.

I asked about the 140-145 grain bullets. No one with any of the four ammo companies consulted knew of any specific studies devoted to these, but the general feeling was that they are heavy enough to burn most of the powder before the bullet leaves the case, and that "ejecta" entering the barrel throat would be similar to that from 158 grain loads. However, some of the 140's have been stoked pretty hot. I sort of prefer to shoot them in heavier guns.

But if you need high velocity from a snub or three-inch .357, those 140's will often deliver over 1200 FPS from a three-inch bbl. Worth remembering, although I wouldn't shoot them routinely in a K-Frame or smaller gun. But I don't use ANY full .357 load routinely in these smaller guns. Use them when needed, or for occasional familiarity firing, but normally shoot.38 Special ammo. Your gun, your hand, and your wallet will appreciate that.

The better Plus P .38 ammo and the "medium" .357 loads are ideal for most self defense work in smaller .357's, especially if you might have to fire the gun indoors. Muzzle blast does not make the .357 ideal in enclosed spaces!

In the great outdoors, it comes into its own, and the K-Mags are handy to wear when you only expect to shoot the gun occasionally (if at all) as you go about your daily business. The backpacker, hiker, or cop will find the lower weight and ergonomic qualities of the K-Magnums much to his liking. The dedicated varmint hunter, who uncorks many rounds of .357 ammo a year, may be better served by a larger .357.

I think it goes without saying that the M-66 conceals better than a M-686 or a Ruger GP-100, when that's a factor.

For what it's worth, if I could have but one handgun, it'd probably be my four-inch M-66, although the GP-100 comes in very close. The Ruger might win mechanically, as it will run longer with heavy use and no repairs. If you don't live near a good gunsmith, that has to be considered.

Back to the original question, I always buy stainless hadguns now, for the reason given above by the gentleman from New Orleans.

T-Star

I read somewhere that S&W changed the stainless steel between the 66 and the 66-1 because of machinability issues. Do you know if they changed the alloy or just the heat treatment?

There is no evidense of a stainless steel 66 being stronger than a 19. There is some stuff on the net about the 19-5 and later 19s with the newer barrels cracking forcing cones versus the pinned and recessed older models.
Maybe someone else has some more information.
Howard

I was told my a self-educated fellow who did MUCH reading on metalurgy when building his own 1,000 horsepower rail dragster that stainless was slightly more elastic than carbon steel. This means that it could deal with the strech and compress rigors of firing slightly better than chromoly.

Experience bore this out too. Over the years I've found stainless fasteners will strech a bit more without snapping than standard steel.

My sentiments exactly!

I have seen the M-19 described as "a 38 that can fire .357s". Don't see why the M-66 would be any different.

I have always heard that forcing cone issues, though rare, were more prevalant on the Model 19.

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"I read somewhere that S&W changed the stainless steel between the 66 and the 66-1 because of machinability issues. Do you know if they changed the alloy or just the heat treatment?"

I remember reading something by Jeff Cooper in which he said the very early Model 60 Chief's Special was made from a "tool grade stainless steel".
According to him, S&W was unsure about what was needed to build stainless handguns, that being early days for stainless in firearms, and chose a stainless that just absolutely ate S&W's tooling up.
They soon changed to a more suitable stainless to prevent tool wear.
Cooper said those first Model 60's could probably have handled full charge .357 Magnum ammo with no problem.

I assume Cooper knew what he was talking about because apparently he had some education in metallurgy.

The Model 60 was introduced in 1965, the Model 66 in 1972, so the type and heat treating issues of stainless were settled by then.

Having instructed and maintained several hundred K frame magnums during the 70's, 80's and thru part of the 90's, both 66 and 19's in 2.5 and 4" bl's with magnum loads, I have always thought that for citizen shooter's & most cops, the concern for splitting forcing cones, cutting top straps, etc. is pretty much a non issue.
I had K frames in the armory that had digested thousands of full power loads, 110 gr, 125 gr, and 158 gr.....and yes after years of use and thousands of rounds, the guns would show wear and tear, both the 66's and 19's. IMO was one more mechanically or structually durable than the other? No.
were the stainless guns easier to keep looking good? Yes.
But I have known very few citizen shooters or LEO's that pound that many full throttle mag's thru a K frame.....shooting full boat magnums rapid fire DA in K frame is not a real fun experience.
I have K frame magnums that I have carried and shot since 1973....a couple of them with over 50,000 rds thru them, about half magnums and the other half +P 38's....yes they have throat erosion and top strap cutting to some extent, but with 38 wc's at 25 yds I can still shoot " rat holes" with them.
As far as "durability", I go with the stainless guns, simply because they are much more immune to moisture, persperation and I don't have to worry about the finish.
I think either a 19 or 66 will serve anybody well, I have been shooting mine for 40 years, and they still get the job done, when I hold up my end.
But if you are serious about shooting tens of thousands of 357 magnums and concerned about beating up your gun, then go to a heavier frame gun.

I agree with my fellow Texan. I have opened up revolver chamber throats using emery cloth on a drill (the LBT method). Carbon steel is tedious, but I won't even attempt doing it on stainless again. After 30 minutes working a coarse emery cloth polishing bob through a Redhawk chamber, there was no measurable difference (to .0001) in throat dimension. I finally gave up.

As to alloys: I'm no metallurgist, nor have I played one on TV, but I recall reading from multiple sources that I can't remember that stainless alloys vary widely from one manufacturer to another, to the extent there was no real standard for what constitutes "stainless" steel.

Wow, this is a 2 1/2 year old thread! Happy birthday!