357 load for old k frame 125gr

[Laketime]

That particular load is why the L frame was developed.

 

[CorvZ061]

I guess final update. The 6.2 gr load of CFE Pistol netted 1171 on average from my 4" Model 19. Very mild recoil impulse and plenty accurate. I think this will be the one I play around with to fine tune.

AA#2 and AA#5 had a pretty wide variation in velocity and left unburned powder on the table. Both of these powders are from 2003, they have been opened and used, but kept in a dark room that's climate controlled (closet in my office/reloading room). I might play around with these for my 686 a little closer to mid/max loadings and see if they clean up any better. Could be bad powder at this point too, I have some data I've used before with some 158gr bullets that I'm going to load again with some 158's I have ordered.

 

[stansdds]

I loaded 15 last night with 6.2gr of CFE pistol, 15 with 7.8gr of AA#2, and 15 with 7.5gr of AA#5. Going with a chrono to the outdoor range today to see how they shoot. Also have 50 full power N110 loads for my 686. Will be a fun morning regardless.

I think you will find that AA#5 is a really nice, medium burning rate powder. At minimum powder charges, it may burn dirty, so if you want low velocity loads, AA#2 may be a better bet. Smokeless powders tend to burn cleaner the closer they are loaded to maximum safe pressure.

Any instances of forcing cone failures with L frames? Or has this been pretty much an issue with K Frame? I would assume J frames have probably experienced it also.

Thanks,

Rosewood

I think the issue with the older K-frames is the flat spot at the bottom of the barrel extension. When S&W moved the gas ring from the yoke to the cylinder (19-4), they had to make that thin spot even thinner for gas ring clearance. I think this is when the forcing cone cracking became a bigger issue.

Could a J-frame forcing cone crack? I suppose anything is possible, but the J-frame does not have a thin spot on the forcing cone, so the impact forces of the bullet entering the cone will be even all the way around the circumference of the forcing cone. I think this lessens the probability of developing a cracked forcing cone.

 

[shil]

The forcing cone on my 19-2 cracked.

Mine, too. Less than 250 rounds of Winchester factory 125 grain .357. Smith replaced the barrel, but that was 20 years ago. Try to find a pinned Model 19 barrel these days. In the infrequent times I've fired the gun since, I've avoided full-power 125 grain ammo, factory or handloaded.

 

[Nevada Ed]

The little 110 & 125 JHP bullets at "Atomic" fps , hitting the forcing cone
was very hard on the M19,

where the slower 145 gr or hevier bullets were a lot easier and closer to the bore
with the 158, actually in the bore, when it finally exited the case, making
bullet alinement and impact a lot softer, on the metal parts.

If you notice, todays 110 JHP ammo has been dropped to the 1200fps area
my a lot of company's, for a better load for the K frames and older guns.

 

[IrishFritz]

I am reminded that the Models 19&66 were specialized police service revolvers developed from the Combat Masterpiece 38. They came about at the urging of Bill Jordan who was a Border Patrol Lieutenant and Elmer Keith to afford police a more effective weapon than the 38. However, they were never intended for a steady diet of 357. The old adage practice with 38 and carry 357 makes sense even today and back in the day most departments including BATF mandated 38 special in the gun and perhaps 357 in the dump boxes. I do not personally choose to give my K frames a steady diet of full house 357's- but that's just me

 

[PeteC]

I would not shoot them in a K frame revolver. That's why the L frame was introduced.

Cracked forcing cones are not a legend, it did happen in the older K frames.

How To Avoid Revolver Forcing Cone Failure | An NRA Shooting Sports Journal

That is an interesting example, but that particular failure, shown in the before and after pics, was likely caused by the erosion which created weak spots in the forcing cone. This was not a Model 19 or Model 66 with the infamous flat spot at the bottom. The forcing cone was already damaged in the "before" pic, and the hoop strength of the metal was reduced. There might have already been a crack, and who knows what kind of ammo was fired from that gun before the author bought it.

The cracks that led to the development of the L-frame were on the bottom, where the forcing cone was flattened in the factory.

 

[Luke Duke]

When I had a Model 66 I shot 6.5 gr of Titegroup .38+p+ still under minimum charge for .357. Or 8.0 of Win 572 which is also a great powder brass just falls out with NO signs of pressure great accuracy. Both low pressure rounds, clean burning and won't be up your gun.

 

[ArchAngelCD]

That is an interesting example, but that particular failure, shown in the before and after pics, was likely caused by the erosion which created weak spots in the forcing cone. This was not a Model 19 or Model 66 with the infamous flat spot at the bottom. The forcing cone was already damaged in the "before" pic, and the hoop strength of the metal was reduced. There might have already been a crack, and who knows what kind of ammo was fired from that gun before the author bought it.

The cracks that led to the development of the L-frame were on the bottom, where the forcing cone was flattened in the factory.

I know a lot of the article didn't directly pertain to the topic but the bottom did. Since I have no way to edit out all but the topic section I posted it anyway. The information within is good even if not directly related. (IMO of course)

 

[rosewood]

The little 110 & 125 JHP bullets at "Atomic" fps , hitting the forcing cone
was very hard on the M19,

where the slower 145 gr or hevier bullets were a lot easier and closer to the bore
with the 158, actually in the bore, when it finally exited the case, making
bullet alinement and impact a lot softer, on the metal parts.

If you notice, todays 110 JHP ammo has been dropped to the 1200fps area
my a lot of company's, for a better load for the K frames and older guns.

So, are you saying the bullet is what is cracking the forcing cone? I always assumed it was the hot gases and pressure of the gases expanding that was doing the damage? Or is it a combination of both?

Thanks,

Rosewood

 

[PeteC]

I know a lot of the article didn't directly pertain to the topic but the bottom did. Since I have no way to edit out all but the topic section I posted it anyway. The information within is good even if not directly related. (IMO of course)

Don't get me wrong, I think it is a great article, and thanks for posting it. All good information. Here is one that talks about the development of the L-frame, including the role of the cracked forcing cones, with pics...

The Smith & Wesson L-Frame Story – RevolverGuy.Com

 

[ruger 22]

I know I might be a bit off beat but I always considered the combat Magnum/Model 19 a 38 Special hot rod. The L and N frames are real 357's. Even Keith in his book 'Sixguns' mentioned that it was a fine gun but not the same as the larger frames models for full 357 loads. I fully understand this model's genesis but think it was a solution looking for a problem since we had and still have very good 38 Special guns and very good 357 Magnum guns.

 

[One Holer]

Correct me if I'm wrong, but isn't flame cutting of the top strap another big concern of shooting hot 125 grain .357 mag loads? That's what I recall reading a long time ago so have always reloaded with 158 gr bullets.

 

[Nevada Ed]

So, are you saying the bullet is what is cracking the forcing cone? I always assumed it was the hot gases and pressure of the gases expanding that was doing the damage? Or is it a combination of both?

Thanks,

Rosewood

It starts with the hot gases cutting into the steel and is finished with the bullet
when the metal is weak enough to fail.

Sort of like a Granite boulder with a 3" hole drilled into it
then filled with water and let to freeze.
The water will expand and crack the boulder.

 

[Forrest r]

I took this bbl off of a 586 that had 75,000+ hot loads put thru it since it's last rebuild.

The 586 bbl's typically last to the +/- 100,000 round count and then need set back and a new forcing cone cut. The timing also needs redone. That bbl pictured above has been redone 2 times already.

I pulled the bbl because it was shot out/loosing fps & accuracy. The non-drive side of the lands is still sharp/crisp. The forcing cone has erosion and the face has flame cutting where it's supposed to. Namely the 6 o-clock position.

Just wanted to put out there what flame cutting and forcing cone erosion look like.

 

[rosewood]

I took this bbl off of a 586 that had 75,000+ hot loads put thru it since it's last rebuild.

The 586 bbl's typically last to the +/- 100,000 round count and then need set back and a new forcing cone cut. The timing also needs redone. That bbl pictured above has been redone 2 times already.

I pulled the bbl because it was shot out/loosing fps & accuracy. The non-drive side of the lands is still sharp/crisp. The forcing cone has erosion and the face has flame cutting where it's supposed to. Namely the 6 o-clock position.

Just wanted to put out there what flame cutting and forcing cone erosion look like.

That information tells me that S&W fixed the K frame problem with the 586/686 series and the average joe (who likely will never shoot that many rounds in the same gun) will never have a forcing cone problem with one.

Rosewood

 

[scooter123]

Take a look at the 38 Special recipe's and take note of the powder charges for your specific powder choice. Then take a look at the powders charges for the 357 Magnum for your powder. Did you notice there is a gap between the 38 Special and the 357 Magnum? That "gap" is the light Magnum territory and where you should be loading for your model 19's. Personally I load my 125 grain loads for my 19-3 to just 950 fps. Yeah it's more of a 9mm load than a Magnum, so what, it works just fine and it's much gentler on my 19-3. BTW, I'll also note that these light weight bullets to require jacking the rear sight to it's maximum to get on center at 50 yards so in practical terms the 158 grain bullets are a better choice for these revolvers. However they are more expensive so I do understand why many choose the lighter bullets.

 

[bmcgilvray]

950 fps with a light 125 grain bullet is closer to being in a gap gap between .380 ACP and .38 Special and is tepid in the extreme.

 

[LostintheOzone]

My first gun purchase was a new 19 in 1975. I put some .38 through it, but predominantly 125gr 357. I was new to handguns and had no idea that it could be detrimental to over do full house loads. I learned. I had no idea of the differences between an N frame and a K frame. I had no thought of keeping a round count. In about a year that gun was loose as a goose and had what looked like the Grand Canyon at 6 o'clock of the forcing cone. That revolver was beautiful, accurate as hell and toast after I got done with it. Don't treat a K frame like you can an N frame.

I have two model 19's that are 95%. I don't shoot anything above 900 fps in those anymore. I bought a model 28 for that. The K frame was originally designed for 38 spl.

I think any load for 38 spl, even +P, would work in a .357 case. I use this AS load.

Alliant Powder - Reloader's Guide

 

[PeteC]

There is lots of discussion about 125gr v. 158 gr on the firing line forums. This is one thread:

Which is easier on my guns? .357 Mag 125 grain or 158 grain? [Archive] - The Firing Line Forums

The consensus seems to be that the 125 gr ammo causes more wear in general (shorter bullet leaving the case earlier among other things), but actual failures only occur in some circumstances and some, definitely not all, guns.

From the article I posted above...

S&W made the flat spot on the forcing cone bigger around 1975, which reduced the hoop strength of the barrel at that point even more, and led to the cracks (premature failure), regardless of wear over time. Not the same kind of failure as would be caused by ignoring the forcing cone erosion due to flame cutting.

Excerpts from article about the development of the L-frame:

When the gas ring moved back to the cylinder with the 19-4 / 66-1 engineering change, Smith & Wesson did not return to the less aggressive cut on the barrel flat that pre-dated the yoke-mounted guns. Although it was no longer necessary to make extra room for the yoke-mounted gas ring, they continued to remove an excess of material from the 6 O’Clock position of the barrel extension. To explain, we can only presume that a certain amount of institutional inertia existed, and the company wasn’t nimble enough to abandon the recent production change and return to the old method, which left more material in place on the barrel flat.
It was about this time that S&W began to receive numerous complaints of cracked barrels in the 6 O’Clock area, and a number of warranty returns for the same.

This S&W Model 66 not only suffered a cracked barrel, but also a cracked frame. (Image from WaGuns.org - View topic - Cracked revolver frame- fixable?)

[Dick] Baker indicated that his first awareness of this barrel cracking problem was circa-1979 (about 3 years after the barrel flats grew larger), when S&W was conducting some endurance testing of the Model 66, using .357 Magnum ammunition. One of the test technicians encountered the “sticky yoke” condition on two of the test guns (unfortunately, Baker did not indicate how far into the test this was, or how many guns were in the test), and upon examination, they were found to have cracked barrels at 6 O’Clock. After becoming aware of this issue in the Stainless Combat Magnum, Baker stated that he went to the Outside Repair Department at S&W, and, “inquired if they had ever seen cracked barrels in the (blued Model 19) K-Frames, and they said they had,” suggesting that the problem was linked to “hot handloads.”

It is a long article, but worth a read:
The Smith & Wesson L-Frame Story – RevolverGuy.Com