357 Mag in K-frame? Probly a rehash.

[Lavan]

I've seen this debated before.
Just got some neat Altamont grips for my 6" M66 and they make me want to use it... LOTS MORE!

But..... I've been Googling and the S&W sites all say the K-frame was developed for the 38 SPECIAL !!!


Well, golly, I know that.

I did find a ref that said the M66 was "durable."

Any of you have a definitive actual TEST data link that applies to the question?

I'm sure there are plenty of ...opinions.... but would like a link to an actual test thing. Like maybe life expectancy for number of rounds of factory .357 in a K-frame?

Thanks.

 

[Model12Win]

The K-frame .357 magnums are durable, but they aren't as durable as an L-frame or N-frame magnum.

Make sure you keep the forcing cone clean of all deposits, as a build up there can lead to a cracked forcing cone when firing magnums. Also, it is advised to limit light and fast .357 loads like the 125 grain full power stuff. That stuff is fine for occasional use and practice, but I wouldn't make it my plinking load.

Obviously, if the K-frame wasn't able to handle .357 magnum, S&W wouldn't have made and sold millions of them in that caliber of many decades. The hold up well if properly maintained. It's not a bad idea to fire mostly .38 special through them though, as they aren't built for extra heavy magnum usage, unlike the L and N frame guns. If I were you, I'd just stick to .38 special for most practice with occasional .357 for familiarization and leave it at that. You should experience no issues with your Model 66.

 

[Lavan]

I used to "carry" the hot 125s in my 640 for the pawnshop use.

GODAWFUL blast and stuff.

What I use in the 66 is the 158 gr. ...aluminum case Blazer ..... 357s and they seem relatively mild. More poop than 38 (which I prefer 148 WC)

I think I only have about 5 boxes of the Blazers and they are all jacketed so I doubt they'll build up gunk in the cone.

But....good advice.

The 357s are VERY accurate but the 38s are more so.

Just delving for data on the round count expectancy. WHICH of course I realize depends a LOT on the load.

Gee, I love 22LR.

 

[5thShock]

My kid has a Model 19. I have looked and not found any formal, definitive test or consistent round count numbers before failure. Our plan is to reload versions of the old 38/44 loads and call it mighty good.

 

[mete]

The story is ---K-frame was used when police use was fire 10 % 357 [for carry ] and 90 % 38 [for practice] ! Then the M19 worked . When they found that police should practice with what they carried the K frame wouldn't hold up well. IIRC that was the explaination of M. Ayoob. Some changes of pressure limits were made and gun details but it really lead to the stronger
"L "frame guns.
If you have a K frame , for long life I would use 38+P rather than 357 !! That'slike the 38/44 round .

 

[reddog81]

You will spend $1,000's if not $10,000's on ammo before you have any chance at hurting the gun unless there was a manufacturing defect present to begin with. The S&W K frame was developed before .357 magnum existed so it would have been impossible to to design the K frame for .357.

There are even smaller frame sizes made for .357 now.

There are no definitive tests out there and any testing would require a very large sample size for it to have any validity. This would be extremely expensive.

Today's factory ammo is supposedly watered down to prevent the cracked forcing cones and extreme top strap erosion that was showing up in the 1970's.

Personally I'm more concerned about the battering my wrist experiences when shooting a box of full strength .357's over the battering the gun experiences.

 

[SSA]

in 2000, 'Gun Tests' magazine found a gun range Model 19 that they figured had about 65,000 rounds through it, mostly 38s.
My model 66 is 18 or 20 years old. Haven't counted rounds. Some years I've shot it quite a bit. Maybe 10% factory magnums, 90% reloads in mag cases, loaded hotter than 38+P. Mostly 158 gr bullets.
No problem so far. Zero.

 

[old bear]

I’ve attempted to locate any definitive proof about the K frames and .357 Magnum ammo, without luck. All I’ve been able to locate is opinions based on personal experience.
The Smith and Wesson Corporation may have conducted scientific studies. If they did, I would be surprised if they would be willing to share then with the public.

Based on my experience of 40+ years shooting .357 Magnum rounds in my assorted K frames, I’ve not experienced any damage to the frame or forcing cone. 99% of the ammo I’ve shot has been 158Gr. bullets, some of which was very hot.

Too many people forget, the K frame .357 Magnum revolvers were designed as duty weapons. Which were intended to be carried a LOT and shot from time to time.

With the improvements in bullets and ammo in general I can see no need to feed any K frame a steady diet of .357 Magnum ammo. That is what L and N frames were made for.

 

[Lavan]

Now I have to break it to my gun that it will have to make do with SISSY loads .....mostly.

I hope it will still shoot for me.

 

[T. O'Heir]

"...actual TEST data..." Kind of doubt anybody has ever tested a 'K' frame(dates from 1899. .357 from 1935.) to destruction using the hot .357 that supposedly wears 'em out. It's the steady diet of hot loads that do it. Not just .357 loads.

 

[mete]

As far as I remember the problems started to appear with large police agencies such as the CA highway patrol. A good statisticalnumber !

 

[mavracer]

How many licks does it take to get to the center of a tootsie pop?

Large charges of slow powder causes forcing cone erosion, erosion is a gradual thing that happens over many firings, larger powder charges with lighter bullets will make it worse. ALL magnum revolvers will suffer forcing cone erosion(I've even seen a GP100 eventually succumb to the effects of thousands of ww296/125gr loads and crack). The K-frame's problem is the bottom of the forcing cone is thin where it has to clear the cylinder and crane.

 

[SaxonPig]

Any machine will eventually wear out. The K frame will not be as sturdy as an N frame for obvious reasons. But I suspect very few owners will shoot their revolvers enough to wear them out.

As for breaking, the stories of the K frames splitting the barrels might be explained by the observations of a former police armorer who worked on hundreds of Model 19s. He said every one with a cracked forcing cone was dirty when fired. He theorized that carbon build up in the cone may cause hot spots that can damage the metal. Sounds logical to me. I only have one K frame 357 and make I keep it clean. So far no problems.

PS: I bought it from a retired federal officer who carried it for 19 years and said he fired at least one box of full power 357s through it each month. That's over 10,000 rounds with no problems.

 

[WIL TERRY]

MY 4" M19 has 49M rounds through it as we speak and is doing just fine thank you very very much ! It is still faster than ANY 6" 357 I ever cronographed and that would be over one hundred of 'em.
And so it goes...

 

[Model12Win]

Now I have to break it to my gun that it will have to make do with SISSY loads .....mostly.

Lavan, 'taint nuthin' "sissy" bout a "hot n' proper" +P .38 special load, such as the vaunted 158 grain LSWCHP "FBI load" round.

Hell, some of us "ol codgers" as it were actually have gun like the Model 10, Model 15, Model 64, and Model 67 that CAN ONLY SHOOT .38 SPECIALS!!! Oh the humanity!!!

But those of us who know how to put lead on target, know we don't need a hot magnum to do the job on two-legged varmants of the homo sapien sapiens kind.

 

[Lavan]

It shoots em both in a passable manner.

And those Altamont grips are suh-WEET!!

 

[ThomasT]

I don't think you have to worry about the durability of the model 19/66 guns. My first center fire gun was a 6" model 19. It was the gun I learned to reload with. I got it in the early 1980s. I tried every 357 load I had powder for in the Speer #10 manual. I shot the snot out of that gun. I went shooting at least twice a week. Then in the early 90s I used it to shoot falling plate matches. I won several trophies with it too.

I don't know how many thousands of rounds I put down the bore. At least half were full bore 357 loads. I didn't exceed the listed loads but I did load to the max allowed in the book. The one thing I did right was I cleaned it after every shooting session.

I never had the forcing cone split, it never went out of time. When I sold it it was just as good as the day I bought it new. I can't remember why I sold it but I sure wish I had it back.

Shoot and enjoy your gun. Don't worry about the crap you read on the internet posted by people who have never even owned one of these guns.

 

[Deaf Smith]

I used to "carry" the hot 125s in my 640 for the pawnshop use.

GODAWFUL blast and stuff.

And how Levan. Mine was the 340PD (titanium 12 oz) and it was like having someone hit my hand with a ping-pong paddle each time I fired it.

I find the K frames like the 66, especially 2 1/2 snubs, a +p+ .38 due to lightness (same goes for my 2 3/4 inch Speed Six). My GP-100 and L frames are much more manageable with true magnums. And my S&W 3 1/2 inch 27-2 is not bad at all except for blast.

Deaf

 

[Homerboy]

On more than one occasion when I called S&W about this issue, i was advised to limit my .357 use in k frame magnums. Jordan invented the k frame .357 to lighten the load in a cops belt. So why would they invent the L frame, a heavier gun, if there wasn't a reason?

The NYSP used the model 10-6 in .357, then the 13. Then they switched to the Model 28 (a way heavier gun) before the 681 came out and they jumped on that. Troopers qualified and carried exclusively .357 Magnum.

Is the issue overblown? Maybe. Probably. And I'm sure care of the weapon is a factor too. But K frame magnums are not the gun to shoot lots of .357 in.

 

[reddog81]

S&W invented the L frame so they would sell more guns.

If the K frames disassembled after a couple boxes of magnum rounds they would no longer be making them. Last I checked they still even make J frames in .357.

The N frame wasn't developed for .357. The K frame wasn't developed for .357. The J frame certainly wasn't developed for .357. No frame ever made was developed for the 44 Magnum. What frame a gun was originally developed for is kind of irrelevant at this point in time.

Anything mechanical is going to break eventually. You wouldn't expect to drive a car 200,000 miles and not have any problems would you?