K Frame & Warm 357

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My K frame magnum experience was not so great.
I bought a used nickel snub Model 19. After about 200rds of magnum ammo (mainly American Eagle 158gn SP), it developed a timing issue. Used gun, I wasn’t too surprised. So I had it looked over by a local smith, a guy who has done work for John Taffin.
After I got it back, it started to develop the same issue after another couple hundred of the same rounds.
I wanted to love that revolver, but I traded it for a 3” GP100, which has been utterly reliable, and very accurate.
I save my K frame love for my 4” Model 15.
 
If you look at the differences in loads of H110 and 296 in some manuals, you realize that even though they are the same powder, there has been some variation in the lots over time. The maximum loads listed have mist likely changed periodically for the same reason. So, I would suggest that when you work up a successful load with it, you note the average velocity from your gun, and check new lot loads against that standard under the same conditions and adjust to a matching velocity if you find your new lot is too frisky.
 
I bought my Model 19-5 around mid 1982. According to Roy it shipped from S&W around late 1980.

There was no internet then. I was afraid of leading so I only shot jacketed bullets. Most of my reloads were 110 grain or 125 grain JHPs from either Hornady or Sierra. I tended towards maximum loads of either W296 or Hercules 2400 powder. The same loads out of a friend's 2" Smith would clear an indoor range out immediately. Great big fireball from a short barrel.

Today I mostly shoot cast bullets. Same revolver, the nickel plating is gone under the top strap but otherwise zero damage.
 

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In the RCBS Cast Bullet Reloading Manual #1 -
357 magnum (handgun section )
w/ 158 gr SWC - GC bullet ( RCBS #38-158-SWC)

16.5 grs of H-110 @ 1243 fps is their listed Starting Load .

The Maximum load is shown as 17.5 grs. - H-110 @ 1307 fps .

Loads are with magnum primers , tested in 6" barreled Ruger Security Six revolver .

Your load of 16.5 grs. @ 1243 fps is a sane loading ... in the modern S&W model 65 it should be just fine ... The revolver is built of modern steels and made to shoot the 357 magnum cartridge ... S&W made upgrades and improvements to the model 65 knowing 357 magnums were going to be fiored in it .

Being i'm a Card Carrying Cajun ... I say ... "CHOOT 'EM " !
I don't think you will have any problems with this sane 357 load ...
I have seen some loads that hit 1500 fps and those Scare the Beejeezus outta Me !
Gary
from down on the Bayou
 
I have a Hornady book that lists 16.5gr H 110 as the max load with their 158grm JHP. Velocity from an 8 3/8" S&W Model 27 is 1250fps.
Primers are Fed 200

Same gun with their 160gr FMJ shows a max load of H110 as 15.9gr for 1250fps.

Another edition shows 15.6gr HG110 as max with the 158gr XTP from an 8" Colt Python. Velocity 1250fps. Primers are Win.

I have a Speer book showing 17.5gr H110 giving 1272fps with their 158gr fired from a 6" barrel Ruger Security Six. Primer is CCI 550.

Point here is different tests, different guns, different times, show different results and what is in the loading manuals is what they did, but its not holy writ and may or may not be what your gun does.
 
K-frames

S&W addressed the issue of wear and tear on K-frames by introducing the L-frame. I would wager that the K-frame magnums were always intended to be shot mainly with .38's, and loaded for duty with magnums. That practice was common in LE circles in that era. If an agency wanted to shoot a steady diet of mag ammo, the big N-frames were the choice. As training evolved, and agencies began to train with what they carried, the K's began to be fed more and more all up ammo.

Not just any mag ammo either, but the hot flash and blast 125 gr JHP, which was the gold standard for stopping power. As I understand it,the combination of the characteristics of the 125 gr load, and the flats on the K -frames, led to examples of top strap cutting. Plus too, the 125 gr load in the K's was a bit of a handful for a lot of officers, many, maybe most, are strangely, not "gun guys". ( I always thought it odd that one in a livelihood where your life or another's might depend on your ability, the handgun was viewed much as a hammer). Policing was becoming more and more diverse as well, not all cops were burly combat vets with some familiarity with firearms. At the same time, the duty belt of officers was growing more and more of a burden, and the big N-frames, suitable for mag loads, added to the load and resulting clumsiness. Enter the L-frame.

Out of production now for some time, if a cone or top strap goes wonky, there is no easy repair. Many years back I yearned for a 2-1/2" M66 round butt, and still do. If I had one, I certainly would not push it.
 
As I understand it,the combination of the characteristics of the 125 gr load, and the flats on the K -frames, led to examples of top strap cutting.

No, it didn't. The "flat" is a relief cut on the bottom of the barrel, at the rear and does reduce the thickness of the barrel at that point, but it has nothing to do with topstrap flame cutting.

Additionally topstrap flame cutting is not a structural issue, it is a cosmetic issue. The blast of certain hot powders out of the cylinder gap will cut a groove in the topstrap steel, but it is a self limiting thing, and does not cut enough metal to weaken the topstrap.

Forcing cone cracking, on the other hand is a different matter and does deadline the gun. And the thin portion of the barrel where the flat is, is the most common place it cracks.

Even when the K frames (models 19 and stainless versions) went to a steady diet of magnum ammo in police use, (including practice) they served normally for quite a while (like through the 1960s) without abnormally high failure rates, shooting the standard magnum 158gr loads.

When the police switched over to the hot 125gr loads for general use (street and practice) that's when problems with forcing cones began to show up at an abnormally high rate. And while gun legend makes it seem like ALL the guns had issues, very few actually did. While I don't have the actual figures, I understand that the "abnormally high failure rate" was something like 7 guns out of 1,000 instead of 2.

AND, sometimes the failures were due to user error. One case I personally saw was a model 19, where the shooter had badly leaded the bore, didn't clean it, and went to shooting the hot magnum ammo, and the forcing cone cracked, literally because it was abused.

From what I've heard, most of the actual problems were mostly with the early stainless guns (mod 65 & 66) and were the result of insufficient testing before the production and Bangor Punta's push to get guns out the door. Can't say for certain, but that's what I've heard. Make no mistake, some guns did fail, it was a problem and it got fixed, but the tales grew in the telling, and the problem was not as widespread as todays stories make it seem.

At the same time, the duty belt of officers was growing more and more of a burden, and the big N-frames, suitable for mag loads, added to the load and resulting clumsiness. Enter the L-frame.

The weight of equipment officers had to carry did go up, quite a bit, but the L frame guns didn't solve that. Not a bit. With the same barrel length, the L frame weighs exactly the same as the N frame. They are NOT lighter. They just balance differently and have a slightly smaller (K frame size) grip frame.

The L frame was not a solution to the weight of an N frame, they weigh the same.
 
Originally posted by 44 AMP
Even when the K frames (models 19 and stainless versions) went to a steady diet of magnum ammo in police use, (including practice) they served normally for quite a while (like through the 1960s) without abnormally high failure rates, shooting the standard magnum 158gr loads.

This is exactly right. The Combat Magnum (later designated the Model 19) was introduced in 1955 yet the problems with cracked forcing cones didn't become well-known until the 1970's and 1980's. While some will say that the early guns were shot primarily with .38 Special ammo, I think it has a lot to do with the fact that, at the time the Combat Magnum was introduced, the only widely available factory .357 Magnum ammo used heavier bullets.

Actually, it's quite likely that, early on, a lot of the ammo shot through K-Frames was hotter than what we have today albeit not with lightweight bullets. Much of the data in older loading manuals shows heavier powder charges than that shown today and a lot of the older manuals suggest magnum primers for powders that are loaded with standard primers today. Also, the original factory ammo for .357 Magnum was purportedly significantly more powerful that that made today. Given that the Combat Magnum was introduced only 20 years after the Original Registered Magnum, it's entirely likely that there was still a good bit of the original 1935-spec ammo floating around.

When the police switched over to the hot 125gr loads for general use (street and practice) that's when problems with forcing cones began to show up at an abnormally high rate. And while gun legend makes it seem like ALL the guns had issues, very few actually did. While I don't have the actual figures, I understand that the "abnormally high failure rate" was something like 7 guns out of 1,000 instead of 2.

It's my understanding that the primary issue with the hot 125 gr loads is one of both powder and bullet length. This ammo was loaded with slow-burning powder in an attempt to eke out all the velocity they could get (I once pulled the bullet from a Remington 125 gr JSP and the powder inside looked an awful lot like H110/Win 296). In addition to this, the 125 gr and lighter bullets are, obviously, shorter than their heavier 158 gr counterparts. The problem with this is that the nose of the shorter, lighter bullets hasn't fully engaged the cylinder throat before the base of the bullet has left the case thereby allowing burning powder and extremely hot gas to flow around the bullet and prematurely enter the forcing cone. Also, due to recoil and their shorter length, the 125 gr and lighter bullets will impact the 6 o'clock position of the forcing cone with greater force than the heavier 158 gr bullets will. This is all explained in greater detail in this article by Butch Kent on Gunblast.com

https://www.gunblast.com/Butch_MagnumLoads.htm

AND, sometimes the failures were due to user error. One case I personally saw was a model 19, where the shooter had badly leaded the bore, didn't clean it, and went to shooting the hot magnum ammo, and the forcing cone cracked, literally because it was abused.

I've heard this too. I find it somewhat ironic in that, if the bore were leaded by shooting something like standard 158 gr LRN .38 Special ammo, then the old saw of "practice with .38's and carry .357's" might have actually contributed to the forcing cone's demise rather than prevented it. If the shooter you mentioned had shot his revolver exclusively with jacketed .357 Magnum ammo, his barrel would probably still be in good shape.

From what I've heard, most of the actual problems were mostly with the early stainless guns (mod 65 & 66) and were the result of insufficient testing before the production and Bangor Punta's push to get guns out the door. Can't say for certain, but that's what I've heard. Make no mistake, some guns did fail, it was a problem and it got fixed, but the tales grew in the telling, and the problem was not as widespread as todays stories make it seem.

I've heard this before. I've also heard that the problem was endemic to some of the specimens produced right after they eliminated the pinned barrels and transitioned to crush-fit barrels as, supposedly, they had some problems with over-torqueing the barrels which could lead to cracking early-on. Either way, we're talking about revolvers produced 40+ years ago now and, most that were going to crack due to factory defects probably did it decades ago.

My take on it is this: if you take care of your gun and avoid .357 Magnum ammo with bullets lighter than 140 gr, a K-Frame will likely last several lifetimes of what the average person is likely to shoot through it. I've personally owned two K-Frame .357's, a 66-2 and a 13-4, and both have been shot while I've owned them almost exclusively with .357 Magnum ammunition (I have other revolvers that I shoot .38's in). Both are just as tight and have forcing cones in just as good condition as the day I bought them, but the Magnum ammo I've shot through these revolvers was almost exclusively with 140 gr or heavier bullets (I think I did shoot one box of 125 gr Remington through the 66 in my intemperate youth). As with most firearms, K-Frame .357 Magnums work best with the ammo they were designed for (158 gr Magnums), but if you start using ammo significantly outside the parameters that the gun was designed for, you're likely to have problems.

The weight of equipment officers had to carry did go up, quite a bit, but the L frame guns didn't solve that. Not a bit. With the same barrel length, the L frame weighs exactly the same as the N frame. They are NOT lighter. They just balance differently and have a slightly smaller (K frame size) grip frame.

The L frame was not a solution to the weight of an N frame, they weigh the same.

This always puzzled me a bit because, while you're correct that most L-Frame .357's weigh the same as a so-chambered N-Frame of the same barrel length, there's no reason why this has to be the case. The reason that L-Frames are so heavy is that the vast majority have heavy barrels with full underlugs while their K and N-Frame counterparts traditionally have half-lug and, in the case of the N-Frames, tapered barrels. While S&W has made a few L-Frames with different barrel profiles like the short-lived Models 619 and 620, they've never made very many for reasons which are unclear to me.
 
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I find it somewhat ironic in that, if the bore were leaded by shooting something like standard 158 gr LRN .38 Special ammo, then the old saw of "practice with .38's and carry .357's" might have actually contributed to the forcing cone's demise rather than prevented it. If the shooter you mentioned had shot his revolver exclusively with jacketed .357 Magnum ammo, his barrel would probably still be in good shape.

One of the problems with "old saws" sayings and rules is that, over time important parts get dropped or left out for brevity, or because "everyone knows" and therefore it doesn't need restating.

Things like CLEANING THE LEAD OUT after shooting .38s BEFORE shooting jacketed .357s.

While S&W has made a few L-Frames with different barrel profiles like the short-lived Models 619 and 620, they've never made very many for reasons which are unclear to me.

Nor are the reasons clear to me, either, though someone at S&W must have reasons for them doing what they do. I always felt that if S&W had made the L frame without the full underlug and perhaps with a tapered barrel they'd have a winner, balancing better than the full underlug guns, and being a bit beefier than the K frame, but lighter than the N frame, and having the K frame grip size.

For whatever reasons, they didn't do that to start with, and the models you mention where they did it, didn't last, apparently due to lack of sales, it seems.
 
Also, the original factory ammo for .357 Magnum was purportedly significantly more powerful that that made today.

This is not true, according to a article in the Shooting Times, May 2023, that looked at the published ballistics of the 357 Magnum since it's introduction in 1935. Todays ballistics are more powerful. This started in 1963 when jacketed bullets were introduced when the 158 grain jacketed bullets were faster (1550 fps, 8 3/8" barrel) than any lead bullets of the same weight listed before then (1510 fps, 8 3/4" barrel). The ballistics reported today of 1235 fps for a 158 grain bullet are from a 4.0" vented barrel, but Remington noted in 1976/1977 that the ammo did not change, just the barrel length.
 
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I have seen period data listing the original .357 158 load at 1500, 1510, and 1550fps from the 8 3/4" Registered Magnum.

And I've seen multiple times when different guns shooting the same ammo show different velocities, even as much as 100fps, so I don't consider a handful of fps to be proof of "significantly" more or less powerful, it may simply be the result of different guns giving different velocities.

With my handloads I have pushed 158s over 1400fps from 6" guns and 125s over 1600. One load went 1620fps in one 6" gun, 1670 in another and 1720fps from a third 6" gun.

However, these are my handloads, in my guns, and are absolutely not suitable for general use in all guns chambered for .357 Mag.
 
I've seen the original 1935-spec .357 Magnum load quoted as 15.5-16 gr of 2400 under a 158 gr LSWC. Every recent (as in the last 20 years) loading manual I've looked in goes no higher than 15 gr of 2400 with either jacketed or cast 158 grain bullets. Also, the original ammo used large rifle primers which, with an equal powder charge, should generate more pressure than the small pistol primers of today's ammo.

While I don't recommend it, I have gone as high as 15.5 gr of 2400 with a magnum primer under a158 gr LSWC only in my N-Frame .357's and, while I wasn't able to chronograph them, the recoil and blast was significantly increased over the factory Federal 158 gr .357 Magnum ammunition I shot the same day from the same gun (4" M28).
 
Elmer Keith writes in his book 'Sixguns" (1955) that the first 357 Magnum 158 grain loads were 15.3 gr 2400 which produced 1510 fps from 8 3/8 barrel. That speed is the same as what is published in the early catalogs (e.g. 1938 Remington).

In Keith's 1935 American Rifleman article he writes, "the powder charge, which varies with different lots of powder, is approximately 15.4 grains Hercules 2400 . . ." for a speed of 1518 fps.
 
once again

Thanks to 44AMP for correcting my erroneous comments. I had the topstrap/forcing cone issue wrong, and he set the record straight. Also, the L-frames were heavy, in fact, the last issue revolver I carried was a 4'" L-frame and it was heavier than a 4" 629 Mtn Gun in .44 mag.

Wrong on both counts and I freely admit it....once again, I stand corrected.
 
One of the problems with "old saws" sayings and rules is that, over time important parts get dropped or left out for brevity, or because "everyone knows" and therefore it doesn't need restating.

Things like CLEANING THE LEAD OUT after shooting .38s BEFORE shooting jacketed .357s.



Nor are the reasons clear to me, either, though someone at S&W must have reasons for them doing what they do. I always felt that if S&W had made the L frame without the full underlug and perhaps with a tapered barrel they'd have a winner, balancing better than the full underlug guns, and being a bit beefier than the K frame, but lighter than the N frame, and having the K frame grip size.

For whatever reasons, they didn't do that to start with, and the models you mention where they did it, didn't last, apparently due to lack of sales, it seems.
The reason I’ve never been a fan of the 686 is I don’t care for the full underlug. I didn’t know they made a 620, now that sucker I’d grab in a heartbeat. I agree a tapered barrel ala. model 27 style would be the frosting on the cake.
 
My uncle had a nice medium frame (I ?) Colt 38spl that had a scallop shaped machine cut in the bottom of the top strap. I think it was original but I’m not positive. I’m also thinking this was done to avoid unsightly cutting of the top strap? Seemed mostly cosmetic to me or were they thinking it allowed the gases to cool down enough to eliminate the gas cutting?
Didn’t some SAA’s have this done too?
 
Drag increases at 4 times the rate of velocity.

The better question is, since that's still only half of even getting to the minimum velocity for rifle level hydrostatic shock level damage, what is your goal that factory FMJ isn't doing?

If you don't have a purpose, which I would argue there is none, it's kind of a difficult question to worry about.
 
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Also, correct me, but the 158gr wasn't the problem. I thought it was established it is the 125gr Remington load specifically that was causing forcing cone problems.
 
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