I'm just now coming back to revolvers after many years using autos on bullseye ranges. When I left them, there was no such thing as an L frame, and I'm scratching my head to figure out what the differences are and why? I understand that the grip size is the same.

I mean, are all 7-8shot revolvers L frames, or does it differentiate by caliber, etc? Does the model number easily tell you the difference? If there's a sticky covering this, can you point me to it? My wife says I can never find anything, unless it calls to me, so probably I've just missed it.

Folks can respond with more technical information but bottom line the L frame is a bit larger than the K to shoot a volume of full load .357 without the risk of damaging the gun. My understanding in some K frames a lot of hot .357 (125 gr) damaged the flat portion of the forcing cone. There is debate over whether this would damage all K frames or just a few and how many rounds would have to be fired and what gr load would/could do damage. The L frame is beefed up to just blast away with .357 and bypass the argument. I shoot .38 in my K frame model 65 and don't need the extra size and weight of the L frame for cc but I would like to have a 7 shot L frame

The L is larger all around than the K, except the grip frame. This was a wise move on the factory's part given the number of K frame stock options that already existed.

The most common L frames are in the 580/680 series, but not all, and there are many 6xx numbered guns that are not L frames. Sorry, just need to do your homework .

There are 6- and 7-shot .38/.357 K and L frames. All 8-shots of these chamberings are N frames. Hope this is helpful.

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Alan
SWCA LM 2023, SWHF 220

So I take it then that the L frames are only used for some of the .357's and (1)5-shot .44mag? That would make sense, for the reasons you've given. Seems that the S&W web-site isn't much of a help though. They list all K/L frame revolvers together, but in the model number details, just call them "medium frames"
Maybe I'll understand this, but then again, maybe not.

They are "medium" compared to the little J frames and big N frames.

I've seen S&W list seven shot 686+ L frames as "large frame" in their catalogs, even though the actual frame size is no different than a six shot L frame which they had listed under "medium frame".

Basically correct. There was a single .40 S & W caliber L frame revolver but you are describing the current line-up accurately. A good book to clarify everything is the Standard Catalog of Smith & Wesson; the 4th edition will be out this summer and current. The last one is now 9 years old.

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Alan
SWCA LM 2023, SWHF 220

Current production S&W revolvers are so beefed up and re-engineered I don't think it really matters much anymore. If it's a new gun, just buy what you like and what fits your needs. The whole K/L/N-frame "this is better than that" debate is no longer relevant.

Older guns, from the '80's and '90's.... there's some merit to it.

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~ S&W aficionado in training ~

I read an article on the reissued model 66. 357 Combat Magnum. the original model 66 was the K framed 357, 6 shot, that was discontinued and the L frame (bigger) took it's place. The article kept stating it was a true K frame in 357 magnum. I guess S&W redesigned something to make the true K frame hold up under lots of 357 magnum shooting.
I'm not sure of what all transpired, but if I were to purchase a new 357 magnum it would be one of the new model 66's.
Right now my model 64 38 special K-frame has come to the top of the most enjoyable, best fitting, most shot and favorite revolver list.
A k frame 357 with adjustable would be a great thing.
A friend has a 7 shot, 357 magnum, ...and I just do not care for it, it's not right. just as soon carry and shoot the N frame model 58.
Gary

Speaking about 38/357 models:
K frame is 6 shots
L is 7
N is 8

Current K in 357 is the model 66, L is 686, N is 627. I'd buy whatever you think feels best or looks coolest.
To me the K frame feels right.

In terms of weight and size, they are actually pretty close. In my hand, an L feels much bigger.

And the guys that are scoping these new two-piece barrel guns, not just the K's, and shooting them from rests, are getting accuracy that's moved to a new higher level. It's amazing how well these new two-piece barrel guns can shoot. Something is going on with the physics, the harmonics, the dynamics, or something on these tensioned barrels.

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~ S&W aficionado in training ~

Let us get technical here because it really does make it easier to understand the differences.

The Key difference between the K and L frame is the diameter of the cylinder. On the K frames the cylinder is 1.450 inch in diameter. On the L frame the cylinder is 1.560 inch in diameter. While this doesn't seem like a very big difference it does mean some critical features can be made just a bit larger. For example because the larger cylinder allows the bullets to be moved outwards a bit there is not only room for seven 38/357 caliber charge holes, the flat present on the underside of the barrel to clear the gas ring on the K frame isn't present on the L frame. In addition there is now room to allow a barrel extension that is about 0.020 inch larger in the L frame. So, not only is the flat that weakened the forcing cone gone on the L frame the barrel is just a bit beefier where it goes through the frame. S&W also made the frame where the barrel is mounted 0.02 inch wider to accommodate that larger diameter barrel extension. Naturally that larger cylinder diameter means the frame window is taller, by about 0.110 inch.

The end result of these tweaks is that the areas in the K frame that demonstrated a higher than desirable failure rate were addressed to solve those problems without adding much bulk or weight to the basic firearm.

Not all L frame .357's are 7 shot. The standard 686 is 6 shot. The 686+ is 7 shot. The L frames mostly have full barrel underlugs, which make them muzzle heavy. There is almost no difference in the total weight of my 686+ and my 627 Pro. There is a big difference in the balance. They may be on to something with the new 66.

I don't know if that's still true with the newer made guns. Say, those made in the last 3 or 4 years. Cuz I don't think the new K-frames have the flat under the barrel anymore.

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~ S&W aficionado in training ~

Now we're getting somewhere. I think it's starting to sink in guys. Now I have an idea of what to look for and, more importantly, what not to worry about. Thanks mucho!!

The new model 66 has the two-piece barrel; on these the forcing cone (barrel shank) is thinner than on the older one-piece barrels, so the yoke clears without the need for the flat bottom on the cone. No reported concerns with this modification but I haven't read about anyone putting huge numbers of rounds (especially the infamous full 125 gr .357s) through one yet.

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Alan
SWCA LM 2023, SWHF 220

They still use the flat under the barrel except in the new Model 66.

The 986 is an L frame chambered for 9mm.