125gr 357 in an L frame

[Abbynormal]

The 125 gr. .357 is what the L frames were made for! A heavier top strap to deter flame cutting.
A larger diameter cylinder to provide for handling more pressure.
Tighter cylinder gap to help eliminate flame cutting. A full barrel underlug to reduce recoil.

All while using existing K frame grips!

Only shoulda' was venting of top strap!

Then it wudda been a S&W's version of the Python!

 

[Dpris]

I was around when the L-Frame was introduced & had one of the first blued 586s out.
I know what the theory was behind the model.
I know what it was built for, and it wasn't built for 125-grainers.

If you persist in saying that the L-Frame was built specifically to reduce or eliminate FORCING CONE EROSION, please tell me exactly how the design does that.

And while you're at it, what in the L-Frame makes it stand up to specifically 125s, as opposed to 158s & 180s in general?

You can get flame cutting in the topstrap from other bullet weights.
The cylinder strength on K-Frame Magnums was not a problem in handling Magnum pressures.

The cylinder gap in L-Frames is every bit as variable as any other frame size S&W builds for .357 Mag rounds & has no relationship to being maximized for 125-grain .357 Mag ammo.

The heavier topstrap was more to resist stretching across all ammo weights than to reduce flame cutting in 125s.


The L was designed to address frame stretch, timing, and cone cracking, which it does.
The underlug was marketing, as a competitor to the Python.
Denis

 

[KEN L]

The main point to remember here is; the L frame was the first platform specifically designed for the .357 magnum cartridge. The only problem that ever arose, that I'm aware of, was from the use of some brands of ammunition with soft primers that caused the back flow issue with the hammer nose bushing. I never had the problem with my gun, but Smith was quick to resolve the issue and will still modify all older guns to this day. There, I said it!

 

[rwsmith]

Flame cutting???

Flame cutting of the strap can happen to any magnum revolver with certain combinations of powders and bullets. It's accepted that flame cutting is self limiting, i.e. the damaged caused will not progress to the point that the strength of the gun will be compromised.

Now throat erosion in an L frame I haven't even thought about. I very rarely use any bullet less than 140 grains in my 686. So I guess I'm out of the throat erosion debate.

 

[Jimmy4570]

It's an issue with the fractionally earlier time frame in which lighter weight bullets overcome crimp and neck tension upon firing to transition into the forcing cone that permits the flame and gases to beat on the barrel entrance. It's an issue for the K frame guns largely over the course of firing several hundreds, into thousands of rounds of full house light weight bullet ammunition. Sticking with properly assembled heavier weight (140 gr. and above) will drastically reduce such wear.

 

[Dpris]

Exact same POTENTIAL erosion issue with any .357 model or brand, if the wrong combination of bullet & powder is used long enough.

The presence or absence of a flat on the bottom of the cone has no affect or influence on gas erosion on the circumference of the cone, and thicker cone walls won't prevent gas erosion.
Denis

 

[RGVshooter]

L frame 357 magnum? You're talking about the 686.

It was designed specifically for continuous long term use of full power 357 magnum loads. There is nothing short of doubling charging with H110 that will hurt that gun.

 

[RGVshooter]

The only problem that ever arose, that I'm aware of, was from the use of some brands of ammunition with soft primers that caused the backflow issue with the hammer nose bushing.

I just wanted to add that although many "purists" cry about the frame mounted firing pin on the newer revolvers as being untraditional, ugly or whatever. People fail to realize that the frame mounted firing pin increases revolver reliability of the gun. On the older models with the hammer mounted firing pin, on some +P and magnum loads depending on the brand, the firing pin would divot the primer to the point of causing it to deform enough that it would make contact with the recoil shield. causing the revolver to "jam".

Frame mounted firing pins allow for a more consistent strike, alleviating that issue with some guns thus increasing reliability.


Which brings me back to the split forcing cone issue on the older K frame magnums. There is a flat spot milled under the forcing cone on the older magnum revolvers that is there to allow clearance for the cylinder. They have been known to crack under some circumstances although I've personally haven't seen it. But apparently it was a issue enough for S&W to design the 686.

 

[Protocall_Design]

On my guns the primer always contacts the recoil shield on every shot. How does that make it jam?

 

[SeamasterSig]

I'm not sure we're the ballistics are on the new 357mg / 125gr that's being offered today. The s&w 357 mg / 125gr jhp that was offered decades ago was 1597 FPS. We're talking full house factory loads.

Buffalo Bore offers a 125 grain JHC that it rates at 1600 fps out of a 4 inch barrel and 1700 fps out of a 6 inch barrel. Now that's HOT! I used to shoot that sort of thing with my 6-inch Colt King Cobra as a sort of cathartic therapy (selling that gun is one of my few firearm regrets). But I'll stick with 158 grains and up for my 4-inch m66-2. That sort of ammo and an m686 are a match made in heaven. Or was it recoil hell? One of those two anyway. Take your pick

There is a flat spot milled under the forcing cone on the older magnum revolvers that is there to allow clearance for the cylinder. They have been known to crack under some circumstances although I've personally haven't seen it. But apparently it was a issue enough for S&W to design the 686.

There may be some truth to that, but I always thought S&W came out with the m686 mainly in response to market demand, i.e. due to the popularity of the Colt Python and King Cobra—to which it bears a certain resemblance.

 

[Pisgah]

It's good to remember that almost anything you "hear a lot of talk about" is doubtful at best, and often entirely false.

When it comes to 125 gr. ammo, it will do absolutely no harm to an L-frame revolver, and the number of K-frames that have been damaged by it is so small as to be statistically insignificant.

If "everybody says", or you hear "a guy at the gunshop told me", your first reaction should always be healthy skepticism.

 

[Warren Sear]

In the summer of 1980, fresh out of college and making good money for the first time in my life, I bought my first new gun, a S&W Model 19-4. I naively used data from an old Speer manual and 125 grain jacketed HP bullets. I shot those overloads exclusively.

The forcing cone cracked at about the 750 round count. S&W repaired the barrel under warranty, but it was my fault. Lesson learned.

So yes, the forcing cone on K frame barrels can crack.

I had a Python at the time when the L frames first came out, and was so disgusted at S&W's attempt to copy that barrel profile that I never could warm up enough to them to buy one. It still really turns me off.

So now if I want that hot .357 magnum shooting experience, it is from one of my N frame revolvers.

(Edited to add) One time I was at a gun range shooting my 6" Python when some clown with a big grin came over and asked, "Is that a Dan Wesson?" My temper being short as it was in those bygone days, he was lucky he didn't get shot!

 

[old bear]

All I can add to the great information already given is, flame cutting on the top strap happens with all revolvers and is considered to be self-limiting.

 

[Tom Kent]

This is an interesting thread. I served a total of 32 years in law enforcement, most of which required a revolver for duty use. The last 12-15 years we were allowed auto pistols and I immediately changed over. The revolvers were required to be 38spl / 357 but we were issued 38spl and required to only carry and use 38spl on and off duty. Our range staff constantly tested ammunition in order to find the best available for our use. I was around when the 125gn rounds hit the market and immediately became the favorite of the gun magazines. My department never approved them in spite of the numerous articles in the gun press crediting the 125gn with the most one shot kills of any bullet at all. Our range staff also considered penetration through car windshields and other items of cover and never went to any bullet lighter than 140gn. I am not demeaning the capability of the 125gn. but we never used them. Then along came the stories of forcing cone erosion, frame cracking in K frame guns and other stories. I doubt that all of these stories are true, based on truth or are all that common. However, in my 38spl, give me a 148gn jacketed soft point and in my 357s give me 158gn jacketed soft point. When I shoot a feral hog I like to see the eyes cross when the bullet strikes. For thin skinned game give me the same jacketed rounds or lead rounds of the same weight. However good the 125gn round is stated to be, I see no need for it and all of the potential problems that can be linked to it. Give me 140gn bullets and up and I will never look back. Just my opinion.

 

[Snapping Twig]

Ball powder (296) and 125g JHP ate up the forcing cone on my first 586.

I'd say, switch to 2400 if you want to push those light bullets.

For me, I'll stick to 160g cast SWC, but that said, I still find 2400 to be premium in the 357. I'll save the 296 for the 44, 454 and 480.

 

[Nanuk]

Don't confuse cone wall thickness (strength) with resistance to erosion.
The L-Frame was designed to resist the CRACKING at the bottom of the cone in K-Frames, NOT to resist erosion from gas cutting.

The L-Frame's cone is just as vulnerable to erosion every bit as much with hotter 125s as the K-Frame was (and still is in the newer Ks).

Erosion is more a function of bullet configuration than cone thickness.
Cracking is a different matter.
Denis

If you shoot 50K rounds thru your 686 and wear out the barrel, just send it in for a new barrel.