I know this has been discussed before, and I really have never gotten a straight answer. I know that there is a possibility of the forcing cone cracking on the Model 19 and 66 K-Frames from using hot .357 loads. I hear some people say using 158 grain .357 rounds is much easier on a K-Frame as opposed to using 125gr rounds? I asked my dad who was a police officer for 30+ years and said when they carried 66's they used 145gr rounds and that he had never heard of the forcing cone issue. Any thoughts, opinions?
Model 66 forcing cone
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diamonback68
US Veteran
I think you've answered your own question. 66s were designed for 158 grain lead and jacketed bullets. Your dad's 145s fall into that same category, in fact that's what I use 145gr Winchester Silvertips. The faster 125 grainers hit the forcing cone with higher speed and hotter escaping plasma gases.
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john traveler
Member
The Smith & Wesson Combat Magnum was introduced in the middle 1950s and named the M19 after 1957 with the introduction of model numbers. For a generation before before this, the only available factory .357 Magnum ammunition was the 158 grain lead bullet propelled by (usually) IMR 4227 or Hercules 2400 powder.
Starting in the middle 1960s, high velocity ammunition of the Super Vel type using 110 and 125 grain bullets became available. That's when the reports of forcing cone cracking started, and also by the 1970s when police departments started training with the magnum ammunition carried by officers.
By the middle 1970s S&W decided that the forcing cone failure was a big enough problem that they introduced the L frame 486/586/686 series revolvers. This larger frame gun eliminated the weak point of the K frame guns: the barrel stub flat needed to clear the crane and gas ring.
The K frame magnums were never intended for continuous firing of magnum ammunition, and that is why so many of them have barrel failures. The L frame guns are rated for continuous use of magnum ammunition with the beefier barrel stub and frame dimensions.
The 145 grain ammunition that your father had experience with was intended to give a bit more velocity and still avoid the reported problems with the lighter bullet weights.
Starting in the middle 1960s, high velocity ammunition of the Super Vel type using 110 and 125 grain bullets became available. That's when the reports of forcing cone cracking started, and also by the 1970s when police departments started training with the magnum ammunition carried by officers.
By the middle 1970s S&W decided that the forcing cone failure was a big enough problem that they introduced the L frame 486/586/686 series revolvers. This larger frame gun eliminated the weak point of the K frame guns: the barrel stub flat needed to clear the crane and gas ring.
The K frame magnums were never intended for continuous firing of magnum ammunition, and that is why so many of them have barrel failures. The L frame guns are rated for continuous use of magnum ammunition with the beefier barrel stub and frame dimensions.
The 145 grain ammunition that your father had experience with was intended to give a bit more velocity and still avoid the reported problems with the lighter bullet weights.
We just go around and around on this topic. I guess I have lived a sheltered existence. I can only recall seeing, in person, one cracked forcing cone on a K-frame magnum. But I have read about it a lot! 
The one cracked barrel I saw was on, of all guns, a Model 13 that had been turned into a PPC gun and probably had had more .38 wadcutters fired through it than anything. Curious, eh?
I have been shooting my Model 19s for quite a few years now and all I can say is I have no hesitation to use .357 Magnums in my guns. I have no interest in any .357 load lighter than the Winchester Silvertip already mentioned, but just because I don't care for light bullets. So, maybe my predilection for heavier slugs has helped me avert disaster, but that does not account for other Model 19 shooters I know who have also used their guns for years without incident. Sure, if I planned to shoot nothing but .357s, I would want the L-frame gun for several reasons, but I think the fretting over the K-frame is somewhat overdone.
The one cracked barrel I saw was on, of all guns, a Model 13 that had been turned into a PPC gun and probably had had more .38 wadcutters fired through it than anything. Curious, eh?
I have been shooting my Model 19s for quite a few years now and all I can say is I have no hesitation to use .357 Magnums in my guns. I have no interest in any .357 load lighter than the Winchester Silvertip already mentioned, but just because I don't care for light bullets. So, maybe my predilection for heavier slugs has helped me avert disaster, but that does not account for other Model 19 shooters I know who have also used their guns for years without incident. Sure, if I planned to shoot nothing but .357s, I would want the L-frame gun for several reasons, but I think the fretting over the K-frame is somewhat overdone.
I agree with this. The San Diego County Sheriff Office issued m66 4" and Remington 125 gr JHP ammo for who knows how long. I would imagine that if all one shot out of the K 357 was the 125 gr JHP (meaning many hundreds or even thousands) then maybe a problem might occur.
I think you will wear yourself out before you will wear out the K 357.
Unless one will shoot 125gr JHP 357 rounds everyday (like a hundred or more a day) I would say it is a non issue. The mag round I shoot out of my 19, 66 and 13 are the 125 JHP.
Pat
I think you will wear yourself out before you will wear out the K 357.
Unless one will shoot 125gr JHP 357 rounds everyday (like a hundred or more a day) I would say it is a non issue. The mag round I shoot out of my 19, 66 and 13 are the 125 JHP.
Pat
amd6547
Member
I have read a lot on this issue, since I shoot a 2.5" Model 19-4, and I do like the 125gn load.
One opinion I have read a few times is that the stainless 66 is less prone to cracking.
This interests me since my Model 19-4 is a frankensmith...I bought it used from a dealer in seized firearms. Nickel, I didn't notice until I got it home that it had a stainless 66 barrel.
I can only guess that my 19-4 suffered a cracked forcing cone, although it has zero flame cutting in the top strap.
In any case, I mainly shoot 38spl and 158gn 357 mag for practice, but carry 125gn.
One opinion I have read a few times is that the stainless 66 is less prone to cracking.
This interests me since my Model 19-4 is a frankensmith...I bought it used from a dealer in seized firearms. Nickel, I didn't notice until I got it home that it had a stainless 66 barrel.
I can only guess that my 19-4 suffered a cracked forcing cone, although it has zero flame cutting in the top strap.
In any case, I mainly shoot 38spl and 158gn 357 mag for practice, but carry 125gn.
dfariswheel
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Seems that many of the "K" frames that cracked had badly fouled forcing cones.
It's thought that the fouling was a contributing factor.
For that reason, buy and use a Lewis Lead Remover Kit from Brownell's.
The Lewis is the only good way of cleaning a revolver forcing cone and it works for lead and copper bullet and carbon build up.
It's thought that the fouling was a contributing factor.
For that reason, buy and use a Lewis Lead Remover Kit from Brownell's.
The Lewis is the only good way of cleaning a revolver forcing cone and it works for lead and copper bullet and carbon build up.
I don't know what I would do without a Lewis lead remover. One of the few things I can think of that is worth every penny you pay for it - and actually a pleasure to use (compared to other things that just don't really work).
S&W made many millions of K framed chambered for the 357 Magnum. Over the last 30+ years as an instructor and armourer I have seen one cracked forcing cone.
However, I have heard from lots of people that knows someone that has a cousin whose wife/husband works with a guy that heard about one that cracked. They wanted to know if it could happen to their revolver. Of course it could happen. A hammer stud could also break or a squib could lock up the revolver.
Even if the number of cracked forcing cones is in the thousands or tens of thousands (it is not that high) you still have a better chance of winning the lottery than cracking a forcing cone.
Enjoy your revolver with what ever factory ammunition that you like. If one day the forcing cone cracks, then look for a new barrel or replace the firearm.
If we all lived in fear of what could happen we probably would never leave our homes.
The usual internet story that you hear about the Distinguished Combat Magnum is that it was designed to give the balance of the Colt Python which was so popular in the matches of that day, people used to put Python barrels on S&Ws as well as Rugers to get the muzzle heavy feel.
However, I have heard from lots of people that knows someone that has a cousin whose wife/husband works with a guy that heard about one that cracked. They wanted to know if it could happen to their revolver. Of course it could happen. A hammer stud could also break or a squib could lock up the revolver.
Even if the number of cracked forcing cones is in the thousands or tens of thousands (it is not that high) you still have a better chance of winning the lottery than cracking a forcing cone.
Enjoy your revolver with what ever factory ammunition that you like. If one day the forcing cone cracks, then look for a new barrel or replace the firearm.
If we all lived in fear of what could happen we probably would never leave our homes.
The usual internet story that you hear about the Distinguished Combat Magnum is that it was designed to give the balance of the Colt Python which was so popular in the matches of that day, people used to put Python barrels on S&Ws as well as Rugers to get the muzzle heavy feel.
I had also heard somewhere that the no dash 66's, like the one i have were made from good metal that was so hard it would actually break the machinery, so Smith and Wesson went to a different metal in the 66-1? Again just a story I heard so take it for what it's worth, sounds like the heavier grain rounds are the way to go.
Sgt 127
Member
I've thought about this alot. Back in the old days, at Dallas PD, they loaded thousands of rounds of 148 GR wadcutters for practice. Lots of lead in the barrel and forcing cone from practice. Then, you would shoot a few jacketed Magnums through it to "clean out the lead".
I've done it myself.
In hindshight, I wonder what kind of a pressure spike we were getting when that screaming .357 Magnum started pushing that lead through the barrel?
I have never managed to crack a forcing cone, but, have seen a couple.
I've done it myself.
In hindshight, I wonder what kind of a pressure spike we were getting when that screaming .357 Magnum started pushing that lead through the barrel?
I have never managed to crack a forcing cone, but, have seen a couple.
Art Doc
SWCA Member, Absent Comrade
I have never heard of a 66 cracking. All 19s to my knowledge and most of them were 19-5s. One theory that makes sense to me is carbon build up from lack of thorough cleaning. Keep it clean and I suspect a K frame Magnum will do fine.
In 30+ years of recreational shooting & competition, and 20+ years in the retail firearms business I have seen 1 cracked forcing cone on a S&W 19. It is a much overstated issue in my opinion.
amd6547
Member
Well, this is the Model 19-4 I mentioned in my post.
I have no idea of its history. It does have case file numbers electro penciled in several places. The price was great when I spotted it in a case at a gun show. I was so happy to find a 2.5" 19 that I didn't notice the stainless barrel in the gun show fluorescents.
Zero trace of any top strap cutting. In fact, when I got it, there weren't even any burn marks on the front of the cylinder (there are now).
It must have had a cracked forcing cone.
In any case, I like it. I call it my Model 19-66..
I have no idea of its history. It does have case file numbers electro penciled in several places. The price was great when I spotted it in a case at a gun show. I was so happy to find a 2.5" 19 that I didn't notice the stainless barrel in the gun show fluorescents.
Zero trace of any top strap cutting. In fact, when I got it, there weren't even any burn marks on the front of the cylinder (there are now).
It must have had a cracked forcing cone.
In any case, I like it. I call it my Model 19-66..
I have bumped into a couple Model 19s that were rebarrelled with stainless barrels. I always presumed it was because the gun needed a new barrel and no Model 19 barrels were available, or maybe that's what I was told... 
Can't recall, for sure. 
Can't recall, for sure. 
M3Stuart
Member
I'm confused; it looks like a nickel 19... Are you saying it's a nickel 19 with a SS barrel? Did I miss something?
amd6547
Member
"...I'm confused; it looks like a nickel 19... Are you saying it's a nickel 19 with a SS barrel? Did I miss something?..."-M3Stuart
You have it correct...nickel Model 19-4 with stainless barel.
You have it correct...nickel Model 19-4 with stainless barel.
I don't think it has to do with any dash numbers or if it is stainless or not.
I think it's more if you carry high velocity factory 125gr, 'practice with what you carry', and practice a lot; you could possibly damage any K-frame .357 whether it's a 13, 19, 65, or a 66. I have to believe it would also erode a 27/28 too but with that thick N-frame barrel, it's not going to crack.
I've only had (or personally seen) one K-frame .357 with a cracked forcing cone and it was a Model 66 but I suspect it had little to do with the gun but more of how it was treated.
The crack is hard to see but it is obviously eroded.
I think it's more if you carry high velocity factory 125gr, 'practice with what you carry', and practice a lot; you could possibly damage any K-frame .357 whether it's a 13, 19, 65, or a 66. I have to believe it would also erode a 27/28 too but with that thick N-frame barrel, it's not going to crack.
I've only had (or personally seen) one K-frame .357 with a cracked forcing cone and it was a Model 66 but I suspect it had little to do with the gun but more of how it was treated.
The crack is hard to see but it is obviously eroded.
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