I'll be receiving a 66-4 about the middle of next weeks but am beginning to get questions in my head about shooting 357 Mag's though it much since I've read here and there about forcing cones cracking...usually at about 6 o'clock. Not that I plan on a lot of full bore fire snorting 357's but was curious as to the credence of and number of these occurrences. I'm sure it has happened as I saw at least two pics from different people showing it. If this had been a serious problem I feel sure S&EW would have addressed it long ago but would like some comments/feedback since this is my first K-frame and don't know it's strengths/weaknesses.

I'll primarily be shooting lead SWC's for the most part so, this shouldn't be a real problem for me-just curious about the forcing cone issue.

The lower part of the forcing cone on K frame .357s is thinner to clear the yoke as it closes. By reputation, the full 125 gr loads cause this to occur most quickly. In my opinion it is likely a matter of repeated impacts on the metal - the more force and repetitions it sees, the more likely it is to fatigue and possibly crack. Some have reported multiple thousands of full-power rounds without problems, however, so limited .357 use will probably never pose an issue for you.

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Alan
SWCA LM 2023, SWHF 220

S&W only suggests using 158gr rounds when shooting .357s through there k frame revolvers for just this very reason. The lesser grain rounds are too hot to withstand a steady diet of them in the k frame platform.

You have more to worry about from an alien invasion from mars than if your Model 66 barrel is going to crack.

Tell that to the ones with cracked barrels.

I don't plan on many, if any, 125 gr loads of 22 gr of H110 but will probably consist of the 158-170 gr lead SWC's and the occasional 135 gr bullet. If I want a fire breathing load I have the GP100 for that...or, the 686.

if you use it the way it was intended that 66 will last a lifetime. use 158 gr. and keep it clean. if you need to hotrod it , get a N frame 27 or 28

[QUOTE]If this had been a serious problem I feel sure S&EW would have addressed it long ago[/QUOTE

They did. It's called the L frame.
I use 158Gr.LSWC's in my M-19's ahead of 14.5 grains of 2400. If I get the urge to shoot anything hotter I use one of my L or N frames.

My guess is few if anyone on this forum have ever experienced this problem. If someone has actually had this happen to a k frame that they own, I'd like to hear about it.

Keep the gun clean. Don't forget the forcing cone area of the barrel. If you don't have a Lewis tool, get one. Limit the use of lightweight magnums. Drew may have overstated his case "just a little" , but in general, if your gun (I take it you are buying a used gun that has been fired) has not been abused before it gets to you, you are not likely to have much trouble with it - as long as it gets proper usage and care.

I carry and shoot a Mod.19-2 that I've had for 41 years this year. It had quite a few of the hot 125's through it before this problem became known,but fortunately suffered no ill effects. These days I consider it a heavy duty .38,and since it's a defense gun piain and simple,I use loads like the 135+P Gold Dot SB 38's, the 158 LSWCHP,and Rem 125 gr. Golden Saber 357's for carry.
It sees some use with 158gr. magnums and 145 gr. Silvertips but those are not very often.
Some of the hot loads used in moderation are fine.The K frames are great carry pieces.

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Blessed be the Lord,my Rock

According to the owner it's had a little less than 500 rounds and from the pics is in excellent condition with no known problems from what I was told. It belonged to a security officer and I don't image he shot all 125 gr Magnum loads when he did shoot it.

All in all, I won't be using it to fire 125 gr Magnum loads but I use cast bullets mostly but occasionally like to try the 135 gr Speer GDHP reloads since that's what I'll be using in it commercially from Speer. Even in the super strong GP100 I don't shoot full blown magnum loads often-maybe 25 or so every few months and that's usually 17 gr of 2400. Six grains of Universal with the 158 gr LSWC is more to my liking.

I , myself do not worry about it. However I do remember reading in Handguns magazine in about 1988-ish the author of the article , Dwane Thomas(?) shot a model 13 with 3" BBL to the point of cracking. He stated that he shot it with nothing but factory 125gr mag for about 6 months or less and 3,000 rounds.

So he basically set out to shoot the gun to destruction and it took quite some time and effort. The crack in the forcing cone was very small and hardly noticeable.

My feeling is a person will go broke from shooting or ruin ones elbows before the gun will wear out.

P

This is fairly recent. Although not a M66 as I'll be getting it's still a K-frame.

The "K Frame Magnum issue" hits me, in a positive way

One would spend many times the cost of the revolver shooting enough of the hot ammo to prove or disprove that there is a problem. Figuring $30/box of 50 for 5000 rounds of hot factory ammo, if you can get hot magnum rounds any more, that's $3000 in ammo. Really hot ammo such as the small niche makers (think Buffalo Bore) is a lot more expensive, and anyone who cares for such is probably using an"N" frame. My recollection is that the NYSP had some K frames that did show the problem, but that they shot a lot, and all full power. I doubt I have the time or the tolerance in my increasingly arthritic hands to make this a valid concern for me.

Could it happen? Sure. Is it a real risk? Not for most of us. If I were inclined to shoot a lot of hot .357s, I'd use my 686 or buy an "N" frame. For those times when greater ballistic performance is needed, I have a .41 magnum, and my converted "N" frame .45ACP coming from Bowen's some day.

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NHI, 10-8.

I load .357 and shoot plenty of it through my M65. The bullet is the weight the gun was designed to use, the 158 grain. The load is 14.5 grains of 2400 which is close enough to "full house" for me. (BTW loading at home costs ~ $13.50/ 50 for some serious self defense ammunition.

There is no risk of cracking the forcing cone with this combination and quite frankly I see no reason to go with a shorter round, either 125 grain or 135 grain, which is the cause of the cracks. With a shorter round the bullet has to jump the gap and has been known to slam into the bottom of the cone upon entry into the barrel.

Hurry Worry
Push and Shove
Looking for Molehills
To Make Mountains of

With all the things going well, why do I fret over irrelevant trifles?

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But then, what do I know?

This is a 66-2 PD "Trade-In". I knew the copper that carried it. He was a gun guy. It had over 13,000 rounds of Federal 125 Grn. JHP Magnums through it before I took it and a bunch of other 66's in on trade.



I gave it a light fluff-and-buff, round butted it and have been shooting the hell out of it ever since. It's a favorite field gun of mine. I have no clue what the round count is now, but it wouldn't surprise me at all to find that it's close to 20,000.



I've owned and shot hundreds of 19's and 66's since the 1970's, including servicing the duty guns for a local PD and I've never personally had or seen a barrel ruined in a K-Mag from shooting hot, light magnums.

As infrequent an occurrence as cracked forcing cones are compared to the zillions of K-mags made, this is a non-issue.

You can baby it if you want to, but you don't need to. Use your 66 in good health and don't worry about it.

Drew

The amount of metal removed from the bottom of the K-frame 357 barrels to clear the gas ring can vary quite a bit between individual revolvers. Some are out there that are very excessive in this regard. Those are the ones to avoid. I used to have a post on the forum that showed several examples that illustrated how much this can vary. Unfortunately it disappeared along with about 95% of my posts after the Great Post Purge a couple of years ago. I don't have the pictures anymore or I'd put them up again. However, you can compare the picture from the thread linked to above with the one of one of my 19's. Quite a difference.



My 19 -

Wow-that is a big difference. There shouldn't be that much but maybe his was during the Bangor Punta days...who knows.

When the gas ring was moved from the yoke to the cylinder in the 13-2 and 19-4 (65-2, 66-1), I think it may have necessitated that change

Good replies in this thread, and plenty more in the many other threads discussing this very issue. Suggest a search.

Bottom line: you're likely safe shooting any common .357 load you like; you're probably especially in the clear if you keep it 140 grain and above.

My understanding is that the 125 grain "hot" loads of today are pale compared to their counterparts from 50 years ago when the forcing cone problems started cropping up and, and that those problems were largely associated with especially hot Treasury loads that briefly became popular in law enforcement circles, and are now long gone.

As I mentioned in my post, this is the first one of these that I have come across, and I have owned a lot of K frame 357's and shoot 357 magnums out of them alot.

For the most part, I thought it was an internet wives tale until I found one for myself. I still have no reservations shooting them.

I ask this question about the M-19 some years ago. Answers were mixed. Some say the force cone would crack after so many thousands of 125 gr Magnums, others said they've been shooting thousands 125 gr Magnums in their 19s and 66s for decades without any problems.

It either will or it won't.

The 110 gr Super Vel rounds were hot when they were around. I still have a few I found a couple of days ago.
I've seen more examples of top strap being eaten from loads useing H110/WW296.

I've never experienced the problem but I was aware of the warnings in the pre-L frame days so I took necessary precautions. I've seen several K's with cracked cones that were for sale and I considered buying until I saw the crack.
As to what load caused it, I don't know but in my opinion it is a real concern.

It doesn't really matter what load. If the barrel is too thin, it is more prone to cracking, whether the bullet weight is 125 gr or 158 gr. The issue with 125 gr and lighter bullet loads has to do with increased rate of erosion. As the forcing cone erodes it become thinner yet, and will aggravate the problem with the thin barrel. But if too much material has been removed, it can crack there sooner or later no matter the bullet weight. As I said, if you see a specimen with too much steel hogged off that area, I'd avoid it if you want to fire magnum class loads through it.

In 1978 I purchased a Model 65, had adjustable sights installed, and carried it on duty with the US Border Patrol. When I transferred to Chicago, I had it chopped to 3”, round-butted, and carried it for another three years. During those nine years, we qualified 4 times a year. The qualification course was the old PPC course. We fired 60 rounds (48 rounds of wadcutter and 12 rounds of magnum.) I don’t know if they were 125 or 110 grain loads. We were also issued 3 boxes of wadcutters each quarter for practice. Practice, for me, consisted of rocks, cans, jackrabbits, and coyotes in the brush and later in Chicago, paper punching. I used up all the issue ammo plus a lot of purchased and handloaded ammo.
When I transferred to Dallas, we were transitioning to semi-autos and the gun was retired to a house gun. I still took it to the range a couple of times a year with both wadcutters and magnums (both 125 and 110 grain.)
After I retired, I joined a local Sheriff’s department where I carry a .45 ACP. I still took my 65 to the range a couple of times a year to qualify with it using all magnums. Sometimes I would use 125s and sometimes 110s. A couple of years ago, during qualification, the cylinder became extremely difficult to open. Upon closer examination it was discovered that the forcing cone had split at 6 o’clock. It is impossible to guess how many rounds have been fired through this gun. However, I can positively state the majority (by a wide margin) have been wadcutters.
By the way, I had the barrel replaced with a 3” Ladysmith barrel. Looks kind of cool.

Attached Images

	Model 65 (2)-001.JPG (58.6 KB, 238 views)
	Cracked Barrel1.jpg (64.7 KB, 186 views)
	Cracked Barrel2.jpg (81.7 KB, 242 views)
	Cracked Barrel3.jpg (80.7 KB, 227 views)

This is what the forcing cone looks like on the 2 1/2" 66-4 I picked up today.

well, don't shoot it at that time, then.

That forcing cone looks fine ColColt. Shoot whatever you wish in that fine 66. Just keep it clean and the forcing cone free of carbon and lead buildup.

Do this and your great grandchildren will be enjoying that 66 decades from now.

I've only been issued/shooting/accumulating/examining K-frame magnums for about 44 years. In all that time I've never seen a 66 with a cracked forcing cone in person. Only a photo of one, on this board. That was after six years of asking if anyone had ever seen or even heard of a 66 with a cracked cone.

I'm with Sebago Son. Better chance of seeing aliens, IMO. Enjoy your 66!! Regards 18DAI

After reading the range of opinions on this subject over the past few months, and with new-to-me 4" 66-2 and 19-4 beauties, I decided to work up a lighter load for a steady diet and to shoot 158 gr. fullhouse loads occasionally. Very probably over-conservative, but there it is. I want to be sure to pass these on. Different story if Smith still made them. Tried a 158 gr. 13.5 gr. 2400 load which chronographed at 1100 fps and was most pleasant. May bump to 14 or 14.5, but honestly, 1100 fps is probably good enough for most of my outdoor use, not living in grizzly country. Skeeter claimed that most magnum loads chrono at about 1200 fps out of 4" barrels but I haven't tested that.

The 19 gr. H110, 140 gr. XTP load goes through my 686, and nicely.

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Keith

I think M29 has made an important point. For all the reports of cracked cones, I have never really heard or read a detailed report of variables. I purchased an old M1917 once and cleaned it thoroughly (I thought). It grouped erratically with FMJs and after a super close inspection of the throat around the barrel, I realized there was ancient lead that had built up there, virtually undetectable at even close inspection. After some serious scrubbing, I had removed all of this old lead, and realized that this could cause some serious back pressure, it's simple physics, combustibles in smaller, confined space, increased pressure (ask the explosives expert about that, and it all makes sense). My guess is that after leading the throat on these K-frames, then firing high pressure light loads just increased the pressure around the throat causing the cracks. Since most probably clean their revolvers well, that would explain the low numbers of reports of this problem. After reading how some clean their weapons on other threads, I realized that this could easily be causing this issue. If 125 gr loads contribute to this problem, I don't see an issue, most (if not all) fixed sight .38/.357 S&Ws are regulated with a 168 gr. load, and I see no real advantage to the lighter since there are simply myriads of 158 grain styles and loads, proven ones to boot. It's all I would ever shoot anyway, J-Frame/K-Frame or even N-Frame.

I have a 547 which produces almost .357 pressures (look it up in the SAAMI if you don't believe me). Ever hear of one of those cracking cones? Maybe it's because most commonly purchased and used 9x19 ammuniton is jacketed. Anyway, it's just my theory on it, I have no proof other than an uninjured firing hand to prove it.

This. Just shoot it!

It's going to have it's debut at the range next Friday. That'll give me this weekend to make up an assortment of rounds and several different powder combos that have worked well with other revolvers. I seldom use jacketed bullets-primarily 150-170 gr lead bullets. I still think I'll stir clear of any fire breathing 357 loads. I'll feed those to the other animals.

So I guess even shooting 38 or 38+ loads with less than 140 grain bullets wouldn't be advisable?

I have a tendency to believe at least some of the cracked cones were due to shooting lead a lot and not getting the barrel/forcing cone cleaned out and it just kept building up. that for sure will cause more pressure. I shoot lead nearly exclusive and after each range session clean them the same day. I usually don't have leading problems at least that a little Chore Boy wrapped around a wire brush and or some Lead Remover by Shooter's Choice won't take care of. If sized properly for you gun -mainly the throats and not using BHN22 bullets in a load that only develops 17-20,000psi, I think leading will either be minimal or not at all.

Lead bullets, whether cast or swaged have nothing to do with it. 38 Special class loads have nothing to do with it. If there was too much material removed from the barrel during fitting, leaving that area thin and poorly supported, cracking becomes more likely with higher pressure loads. If the forcing cone has sustained a lot of erosion, leaving that area thin, it becomes more suseptable to cracking with heavy loads. Thinner = weaker, it is as simple as that.

True but, you can bet an accumulation of lead plays a big part as well-smaller area for bullet to travel though=greater pressure.

Its likey a person will have a heart attack and die before cracking a forcing cone on a model 19. Use the recommended round which is a 158 gr magnum and clean the forcing cone of lead deposits. Also, it would take many thousands of rounds for a K frame magnum to wear out with end shake. The K frame magnum is not a fragile revolver. In my opinion it still the besting all around magnum S&W ever made.
Regards,
Howard

That's very good info. That barrel looks real thin. On the second pic, it appears to be filed at 6 o'clock: is it factory original?

L.

Yes, that was the factory original barrel. However, remember that it was removed once to shorten it. I don't know if that had any bearing on the topic at hand or not.

Thanks for the answer.

L.

I was fortunate to get a good deal on a model 19 with a split forcing cone because I also found a replacement barrel to put on it. Don't have pictures, but it wasn't that long ago. Replacement barrels are getting harder to find . . . .

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