L Frame 617?

[Arrdy]

Hi guys, I'm new here but not new to S&W's.

I have a 617-3 SS 6" with full underlug. I'm being told, some what rudely I might add, that S&W never made a L frame 617.

I've put this 617 along side my 686-5 4" and the frames measures within a few thousands of each other right down to the frame openings for the cyl.

From what I've read here, the only difference between a K and L frame is the strength of the metal. If so, wouldn't that make this stainless 617 an L frame?

Thanks.

 

[colt_saa]

No a 617 is a K-frame

 

[Arrdy]

I'm confused.

If the frames are the same size and material, why is 1 an L frame and the other a K?

Could you explain please?

"I just gots to know!"

 

[RdrBill]

Arrdy.
You make a good point. You might not find any agreement here.
By definition a 617 is a K frame, although a stainless K frame is called an F frame by S&W factory.
There may be a technical engineering difference , or it may be a wording difference. I an certain that 1 or 2 engineers and accountants at S&W know the reasoning for the variations.
Enjoy shooting the gun, let the trivia flow on by. Trivia will cause arguments.
They look like this when shot all morning.

Resembles an L frame which in stainless is an H frame.

Bill@Yuma

 

[Arrdy]

Arrdy.
You make a good point. You might not find any agreement here.
By definition a 617 is a K frame, although a stainless K frame is called an F frame by S&W factory.
There may be a technical engineering difference , or it may be a wording difference. I an certain that 1 or 2 engineers and accountants at S&W know the reasoning for the variations.
Enjoy shooting the gun, let the trivia flow on by. Trivia will cause arguments.

Snip 8<

I've thought a bit and maybe it's the barrel threads. The forcing cone on the 686 is +0.030 then the 617. Might have done it so some joker can't mount a .22 LR barrel where a .357 Mag belongs.

Any other ideas or solid knowledge?

Bill you must be OCD .... those grips are too clean.

 

[PMRet]

The 617 is a K frame, the 686 is an L frame. The L frame is larger than the K frame, from the barrel/barrel lug, to the cylinder, to the cylinder window, to the frame itself. A quick measurement shows about 1/8" difference everywhere, and that's a big difference in strength when you're talking about steel.

Even though the dimensions of the 686 are larger, the 617 actually weighs slightly more (42 oz. to 41 oz. when comparing 4" versions) but of course that's because the .22 bore is much smaller than the .38/.357 bore, leaving more steel in the barrel and cylinder of the 617.

It's obvious to the naked eye that the 686 is visibly larger than the 617, as illustrated by this picture.

 

[fyimo]

The 617 is a K frame, the 686 is an L frame. The L frame is larger than the K frame, from the barrel/barrel lug, to the cylinder, to the cylinder window, to the frame itself. A quick measurement shows about 1/8" difference everywhere, and that's a big difference in strength when you're talking about steel.

Even though the dimensions of the 686 are larger, the 617 actually weighs slightly more (42 oz. to 41 oz. when comparing 4" versions) but of course that's because the .22 bore is much smaller than the .38/.357 bore, leaving more steel in the barrel and cylinder of the 617.

It's obvious to the naked eye that the 686 is visibly larger than the 617, as illustrated by this picture.

+1 on what he said.

 

[Camster]

+2.
The same grips may be used on both,but the cylinder size and window is larger on the L.

 

[Arrdy]

I'm not trying to pet the dead puppy here, I'm just one of "those guys" who like to ask questions. Drove my old man and teachers crazy.

Ok, I measured the areas that were mentioned and the differences are in the yoke window height and the height of the cyl. window. The 686 has the higher window but the lengths are the same. The cyls. are the same length.

It looks like they took the same blank and the difference between the K and L on these 2 guns is "How big the holes are." Externally they are identical otherwise (including the front of the frame, lug to cyl. opening). This is why I was so confused, the differences are so minor between these two.

Thanks guys for the grey matter stimulus.

 

[scooter123]

Just to clarify things a bit, the major difference between the K and L frame is the Diameter of the cylinder. In the K frame the cylinder measures 1.45 inches in diameter, on the L frame it's 1.56 inches in diameter. Naturally, to accomidate the larger diameter cylinder the frame window in the frame is larger.

I'll also point out that in terms of strength, the L frame is stonger in just one single aspect. That is that the L frame doesn't have a flat on the underside of the barrel inside the frame to clear the gas ring on the front of the cylinder. That flat has caused problems with the K frame 357 Magnums when a light weight bullet is loaded at the high end of the scale. What can happen is that the forcing cone of the barrel will split right down the center of that flat. On the L frame, because of that larger diameter cylinder, the barrel is just a bit further from that gas ring on the cylinder so that barrel doesn't need to have a flat machined in it. BTW, I've checked the top strap and the frame under the frame window with digital calipers and these areas have sections that are basically identical, so it's not really a stronger frame, just a stronger barrel.

 

[JamesArthur60]

It's obvious to the naked eye that the 686 is visibly larger than the 617, as illustrated by this picture.

All my naked eye sees quickly is the triggers look different. Why is that?

 

[Arrdy]

I'm going to post pics of these 2 pistols, probably won't be until the weekend tho, class all day tomorrow and a MRI on Friday will be taking most of my time.

One of my jobs as a draftsman was reverse engineering worn out machine parts and upgrading them if possible. Also did some work at stock reduction and part standardization. Manufacturing saves $$$ with the less parts they have to inventory ... and these 2 frames appear to be a very good example of that.

Thanks again for all the input.