K-Frames and Hot Loads

[max]

I have read the various posts about cracked frames, etc. However, I was wondering if you loaded 115 gr jhp's as designed for the 9mm would this be easier on the forcing cone? I very seldom load the top loads listed. I tend to back off a couple of grains just to be safe.

 

[Vulcan Bob]

Normally most damage to the k frame has been in the model 19 with 125gr magnum loads. Damage was usually a split forceing cone. As a rule I only use 158gr bullets when loading hot for a k frame. I am told that the whole forceing cone issue was a result of bullet length rather than bullet weight. Something with the shorter bullet not sealing the barrel cylinder gap long enough. Im sure some one here more knowageable than me will chime in.

 

[ISOM]

Hot loads in a Model 19

Shooting since 1959.
The model 19/"K" frame was designed for the police to carry. Not to shoot all the time.
If you are going to shoot hot loads consistantly get an "N" frame revolver. A Dan Wesson and all the Rugers are designed to take the punishment!

 

[max]

I shoot 999 light loads for every 1 "hot"load. I suppose I am just looking for something more of a +P load. I was thinking that I could buy a thousand or so 9mm jhp's and also use some in 357 loads.

 

[john traveler]

The problem with loading 9mm JHP is that most, if not all 9mm jacketed bullets lack the crimping cannelure needed for crimping .38 Special and .357 loads. Without a proper and secure crimp, your bullets may jump and cause cylinder jamming problems.

The other problem with using 9mm bullets is that they are a nominal .355" to .356" diameter, notably smaller than the nominal .357" to .358" of .38/.357 caliber bullets. This may seem a small difference, but it can cause visibly mediocre accuracy. In some guns, it will give lousy accuracy. I've also encountered a few bore obstructions from using .356" bullets in .38 Special and .357 Magnum cartridges.

Some, although generally, very few revolvers may actually benefit from firing 9mm bullets. A tight bullet-to-case assembly is required, and this usually means a tighter sizing die, or a smaller diameter expander plug, or both. In a few cases, case neck sealant may also be required.

 

[Bullseye Smith]

I think the main problem is the flame cutting that the 125gr. has with the 357mag. The flame on the first round heat up the barrel and the second round starts the cut and with rounds 3 to 6 cuts the barrel or forcing cone. This is when they are shot double action as fast as you can on all 6 cylinders. Plus it won't happen every time, depends on the metal in the barrel. All of this is here say, never seen one or repaired one like this. All of the above was told to me by a S&W smith. This is the reason that the 686 was made and you can't buy a new 357 "K" frame.

 

[colt_saa]

Vulcan Bob is close.

The erosion is caused when shorter projectiles are used with maximum charges of hot fast burning powders like H110 and 296. The shorter projectiles allow the instant of peak pressure to occur after the B/C is open. With longer projectiles the instant of peak pressure occurs while the B/C is still sealed. The longer projectiles also take more time to accelerate because they are heavier.

You can use any projectile you want if you are looking to load 38+P velocities in the 357 Magnum cases. These will not cause trouble because your powder choice will be different. Probably 231, 800X or Unique.

As to 9MM projectiles in 357 revolvers, there is lots of internet myth and innuendo floating around on this subject. When we talk about a diameter of 357 in a barrel we are actually discussing the groove diameter of the barrel, not the bore diameter. Bore diameter is Dependant on how tall the rifling is.

If your particular firearms bore diameter (not groove diameter) will engage the projectile, accuracy is no different than using a projectile intended specifically for the 357. This means tall rifling. If your rifling is shallow and does not grab the projectile, accuracy will be poor. The only way to determine this is to slug the barrel.

Even among the same make and model of firearm these things change. S&W barrels were broach cut 10 or so years ago, today they are EDM rifled.

Ballard rifling, button cut rifling and hammer forged rifling are usually not a problem. Microgroove rifling and polygonal rifling usually are a problem. Then there is EDM rifling which can go either way.

There is only one way to know if they will be accurate in your revovler.......load some and shoot them

 

[LoboGunLeather]

The K-frame .357 magnums are not the ideal platform for .357 magnum ammunition. I am confident that occasional use of the K-frames with factory-spec ammunition is safe and will result in no harm, but it should be kept in mind that the K-frames were not originally developed for magnum chamberings.

Most incidents in which firearms are damaged by reloaded ammunition involve someone attempting to achieve maximum performance. In my estimation, this is foolish.

There is no reason to push any firearm to maximum capacity. Reasonable safety margins can be maintained while still achieving very high levels of performance.

If you wish to achieve maximum performance levels in .357 magnum you probably should have a stronger revolver, such as a N-frame.

If a .357 magnum does not offer sufficient performance levels for your purposes, purchase a .41, a .44, a .500, etc.

 

[pownal55]

i have fired several thousand rounds of 110gr and 125gr jacketed bullets out of two different k frames and never saw a cracked forcing cone. these were max loads with the slow burning powders h110, 296, and 2400. after 6000 rnds of hot loads through my model 27 i realized that all the guns needed tune-ups and some small parts replacement. i have since changed my habits and shoot moderate handloads in all my guns saving the hot stuff for specific shooting. if you feel the need to shoot a steady diet of hot loads a ruger would be a better choice.

 

[colt_saa]

but it should be kept in mind that the K-frames were not originally developed for magnum chambering.

So what? This is just another bit of Internet myth being passed along.

N-frames were not originally developed for magnum chambering either. However they have been doing just fine since the introduction of the World's first Magnum cartridge back 75 years ago.

J-frames were not originally developed for magnum chambering. However they have been doing just fine since the introduction of the first 357 J-magnum revolver 13 years ago. In fact one of my original J-magnums has just about 7000 rounds of full magnum ammunition through it so far. It has never seen a single 38 Special in it's chambers.

What made the K-frame 357 magnum revolver viable in the late 1950s is advances in manufacturing, heat treating and metallurgy. This was not simply a 1955 38 Special cylinder bored longer. If it was, it would have blown up.

Same with the J-frame 357 Magnum introduced in the late 90s. CNC manufacturing and and newer stainless alloys and other materials made this pocket powerhouse possible.

357 Magnum is one of my favorite cartridges. I shoot one of my 357 Magnum firearms at least once a week, twice if I can get away with it. I go through 4000+ rounds of 357 ammunition each year.

 

[rcamp]

I have always assumed a model 66 would hold up to the magnums, having been developed after the problems with the Mod.19. Am I incorrect?

 

[colt_saa]

I have always assumed a model 66 would hold up to the magnums, having been developed after the problems with the Mod.19. Am I incorrect?

Your question is hard to answer. I will address it in a few parts.

Part 1) Is a model 66 stronger than a model 19? If they are of the same era, say both made in 1990, than the answer is no. If you are asking is a 2005 model 66 stronger than a 1957 model 19, the answer is yes but probably a negligible difference.

The truth is that the carbon steel used in the manufacture of firearms is stronger than stainless steel used in the manufacture of firearms. Stainless is popular because it is more corrosion resistant. It saves manufacturers the cost of blue or nickel finishes and customers are willing to pay more for it.

Part 2) Can a model 66 hold up to the magnums? This is entirely dependent on your personal definition of hold up to the magnums. If you are talking about 3000 magnums per year then any S&W chambered for the 357 Magnum cartridge that has ever been made will give you many years of service.

If you are talking about 3000 magnums per week, then most any S&W chambered for the 357 Magnum cartridge that has ever been made will will need to have parts replaced several times per year.

Part 3) What magnums are you referring to? 110 grain projectiles? 125 grain projectiles? 140 grain projectiles? 158 grain projectiles? 180 grain projectiles? 200 grain projectiles? Perhaps something custom?

As has been stated previously in this thread, projectiles weighing 125 grains and less loaded to full magnum velocity will accelerate forcing cone erosion. This does not mean that the firearm has not held up, it just means that the barrel will need to be replaced. If left unattended this could cause a forcing cone crack.

If you are shooting the heavy weights like the 180s and 200s, you will need to pay constant attention to the screws remaining tight. These projectiles are also known to cause premature wear to various parts of the lock work.

 

[Loco Weed]

I am told that the lighter bullets, 125 gr and lighter, have a much shorter bearing surface and so tip slightly when fired. They enter the forcing cone at an angle and usually strike at about 6:00 o'clock and that is where forcing cone cracking can occur. I would stick with heavier bullets. I am also told that the model 19 was designed for the 158 gr bullet only. If you want to shoot a lot of light, hot stuff then use an L or N frame revolver.

 

[colt_saa]

I am told that the lighter bullets, 125 gr and lighter, have a much shorter bearing surface and so tip slightly when fired. They enter the forcing cone at an angle and usually strike at about 6:00 o'clock and that is where forcing cone cracking can occur. I would stick with heavier bullets. I am also told that the model 19 was designed for the 158 gr bullet only. If you want to shoot a lot of light, hot stuff then use an L or N frame revolver.

Someone is pulling your leg. Even if the projectiles tipped prior to entering the forcing cone, there is no way that they would always tip down.

If you take out your K-frame revolver and open the cylinder you will see that the bottom of the forcing cone has been cut away so that the crane can close. This is the reason that most K-frame forcing cone cracks occur at the 6 O'clock position, it is the thinnest part of the forcing cone.

As to the model 19 being designed for the 158 grain bullet, this is also urban legend. The model 19 was designed for the 357 Magnum cartridge. No manufacturer would take the time and money to design a firearm for one and only one loading of a specific cartridge.

In 1955, 125 grain JHPs did not exist yet. Neither did the 110 grain projectiles. These were part of the advancements in ammunition that came in the early 70s.....Thank You Super Vel.

The accelerated erosion that the 125 and 110 grain 357 Magnum loadings cause in the Model 19/66 family of revolvers is no different than what they cause in a L-frame or an N-frame.

The L-frames major strength revision was to raise the centerline of the barrel so that the forcing cone could be complete all the way around. That make the L-frame les susceptible to a forcing cone crack, but changes nothing about the accelerated forcing cone erosion.

Also you need to define what you mean by "If you want to shoot a lot of light, hot stuff" If by "a lot" you are talking about 1000 per year, this is no big deal to a K-frame. If you are talking about several hundred each week, then this is a concern. The phrase "a lot" means totally different things to each of us.

 

[rcamp]

good answer colt saa, that makes sense to me.
Thank you.

 

[TYFOON]

Is it just grain or is it velocity?

I was told that a 1200-1300fps was less corrosive than 1400fps regardless of weight projectile.


Sh@t, first revolver and I ordered 100 rounds of Rem. Goldsaber 125gr. 1250 fps 418 ft/lbs.

Guess those are ok to shoot before going to a 158 grain diet?

Foon