Leslie Sapp
Member
I know they are very close, but what are the technical differences? What actual measurements are different on these frames? Does anyone have drawings that show the dimensions of the various S&W frames?
I Frame vs. J Frame Questions
- Thread starter Leslie Sapp
- Start date
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The distinction is a little more complicated than you might think because there are some engineering and evolutionary design changes within each frame size in addition to the basic measurement differentiation between them. But in general the J frame has a slightly longer cylinder and a slightly longer grip frame. It also has a larger, more oblong trigger guard in its mature form. We're not talking huge measurement differences here -- about a quarter of an inch, perhaps.
I have not much concerned myself with actual measurements, because if you remember which models were built on which frames at which times, the distinctions are clear enough between the two.
Somebody is bound to be along who can address the exact dimensional issues for you, but here's the overview.
The first J-frame was the Chiefs Special in 1950, and then that line expanded with the Centennial and Bodyguard soon thereafter. The main advantage of the new J guns is that they could chamber .38 Special, which the I frames would not.
The prewar I-frame models that continued after the war went through a variety of improvements that made them more J-like in the course of the 1950s without much modifying frame dimensions, and then they were all moved over to the J-frame platform in 1960/61.
Within the J-frame, the trigger guard guard got larger a couple of years into the 1950s, and then the introduction of the J-Magnum frame a couple of decades back gave a second, slightly longer and stronger J platform for guns that could fire the .357 Magnum round.
I have not much concerned myself with actual measurements, because if you remember which models were built on which frames at which times, the distinctions are clear enough between the two.
Somebody is bound to be along who can address the exact dimensional issues for you, but here's the overview.
The first J-frame was the Chiefs Special in 1950, and then that line expanded with the Centennial and Bodyguard soon thereafter. The main advantage of the new J guns is that they could chamber .38 Special, which the I frames would not.
The prewar I-frame models that continued after the war went through a variety of improvements that made them more J-like in the course of the 1950s without much modifying frame dimensions, and then they were all moved over to the J-frame platform in 1960/61.
Within the J-frame, the trigger guard guard got larger a couple of years into the 1950s, and then the introduction of the J-Magnum frame a couple of decades back gave a second, slightly longer and stronger J platform for guns that could fire the .357 Magnum round.
The first I frames had a leaf mainspring, like the K and N frames. Post WW II, they were adapted to the coil mainspring like the J frame. DC covered the rest in his post.
ColbyBruce
Member
Here is an I frame photo.
Inside showing the leaf spring.
SB J frame and the I frame.
Inside showing the leaf spring.
SB J frame and the I frame.
OLDSTER
Member
I frame
I know where I can get one in nice shape for a reasonable price. The little guys have always intrigued me. Is there any reason a good one cannot be a fun shooter ??
I know where I can get one in nice shape for a reasonable price. The little guys have always intrigued me. Is there any reason a good one cannot be a fun shooter ??
I know where I can get one in nice shape for a reasonable price. The little guys have always intrigued me. Is there any reason a good one cannot be a fun shooter ??
Nope. I've owned several pre WW II .32 Long I frames and they have all been fun shooters. At least one of them had a bulged barrel, but it still shot fine.
The I frame went through a number of evolutionary changes before being discontinued, but the main difference between the I frame and the J frame is the length of the frame window (cutout for the cylinder). The J frame was introduced because the I frame wouldn't accept a .38 Special. The J frame has evolved quite a but too.
The I frame window is a hair over 1-1/2" long (about 1.53").
The J frame window is 1-5/8" long.
The current J-Mag window is 1-3/4" long.
OP
Leslie Sapp
Member
I got started down this path while looking for an appropriate holster for granddad's 32-20 1905 hand ejector. I was also looking at IWB holsters for a Chief's Special at the same time, and it got me wondering.
(I have to be careful about that, it usually ends up with me spending money)
(I have to be careful about that, it usually ends up with me spending money)
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FUN TO SHOOT ?
When I was at the range the other day, it occurred to me that there was no more recoil than a 22. That'd make a "walkin' around" gun.
Lobogunleather can help with holsters at reasonable prices.
His IWB rig fits both I and J frames quite well.
TACC1
When I was at the range the other day, it occurred to me that there was no more recoil than a 22. That'd make a "walkin' around" gun.
Lobogunleather can help with holsters at reasonable prices.
His IWB rig fits both I and J frames quite well.
TACC1
Green Frog
Member
I know where I can get one in nice shape for a reasonable price. The little guys have always intrigued me. Is there any reason a good one cannot be a fun shooter ??
The only reason I can think of is that if you let somebody else keep on owning it!
I'm at the stage of I-frame ownership where I just "need" one more (at a time, that is! 
) My two favorites are probably my 32 HE Snub from about 1950 and my rebarreled 6" Heavy Frame Target from the mid- to late Twenties. But then there's the 6" Regulation Police in 32 and the... but you get the idea, don't you? I'm definitely hooked on small frames with leaf mainsprings.Froggie
ColbyBruce
Member
Here is my departed I frame with my K frame 66-2 snubbie. There was a world of difference in weight, size, recoil, noise, and power.
Leslie,
HORIZONTAL MEASUREMENTS:
Frame windows:
J Frame window: 1.635”
I Frame window: 1.505”
Difference: .125” or 1/8”
Cylinder lengths:
All .32 & .38 I frame post war cylinders pre and post M 1953 are the same length; 1.250” + or - .002” as the SCSW indicates.
.22/32s I frame cylinders have some quirky anomalies:
Pre war HFT is 1.201”,
Pre war Kit Gun measures 1.310”.
Post war Model of 1953 Kit Gun is 1.305”
and a M 34 KG is 1.390”
J frame 38 Special is 1.530”, 22/32 Kit Gun is 1.490”
VERTICAL MEASUREMENTS:
Pre war I frames:
22/32 HFT (1925) 1.290” cyl OD, 1.328” window.
22/32 Kit Gun (1935) 1.255 cyl, 1.288” window.
Post war I frames:
M 1953 22/32 KG (1955) 1.264” cyl, 1.303” window.
M 34 (1957) 1.304” cyl, 1.340” window.
J frames:
M 34-1 1.305” cyl, 1.339”” window.
Post war I frame .32s and .38 S&Ws cyl OD and vertical window measurements:
I measured post war .32s and .38s which cylinders are nominally 1.305” to 1.310” O.D. and the vertical frame window dimensions are nominally 1.335”.
Pre war .38 S&Ws measure the same as post wars but the .32s do not!
Pre war and early post war Transitional .32 cylinder O.D.s are nominally 1.267” and the frame windows are nominally 1.304”. This includes a 1957 .32 Target 4”.
HORIZONTAL MEASUREMENTS:
Frame windows:
J Frame window: 1.635”
I Frame window: 1.505”
Difference: .125” or 1/8”
Cylinder lengths:
All .32 & .38 I frame post war cylinders pre and post M 1953 are the same length; 1.250” + or - .002” as the SCSW indicates.
.22/32s I frame cylinders have some quirky anomalies:
Pre war HFT is 1.201”,
Pre war Kit Gun measures 1.310”.
Post war Model of 1953 Kit Gun is 1.305”
and a M 34 KG is 1.390”
J frame 38 Special is 1.530”, 22/32 Kit Gun is 1.490”
VERTICAL MEASUREMENTS:
Pre war I frames:
22/32 HFT (1925) 1.290” cyl OD, 1.328” window.
22/32 Kit Gun (1935) 1.255 cyl, 1.288” window.
Post war I frames:
M 1953 22/32 KG (1955) 1.264” cyl, 1.303” window.
M 34 (1957) 1.304” cyl, 1.340” window.
J frames:
M 34-1 1.305” cyl, 1.339”” window.
Post war I frame .32s and .38 S&Ws cyl OD and vertical window measurements:
I measured post war .32s and .38s which cylinders are nominally 1.305” to 1.310” O.D. and the vertical frame window dimensions are nominally 1.335”.
Pre war .38 S&Ws measure the same as post wars but the .32s do not!
Pre war and early post war Transitional .32 cylinder O.D.s are nominally 1.267” and the frame windows are nominally 1.304”. This includes a 1957 .32 Target 4”.
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Colby,
Your photo below is misleading because it's an apples and oranges comparison due to very different vintages; a Model 36 J frame top and Pre Model of 1953 I frame bottom. Model of 1953 I frames and the Model #'d I frames, .22/32s,.32s and .38 S&Ws, will look just like your Mod 36.
Here is a J frame pre Mod of 1953:
And here is an I frame of the same vintage, pre Mod of 1953:
Your photo below is misleading because it's an apples and oranges comparison due to very different vintages; a Model 36 J frame top and Pre Model of 1953 I frame bottom. Model of 1953 I frames and the Model #'d I frames, .22/32s,.32s and .38 S&Ws, will look just like your Mod 36.
Here is a J frame pre Mod of 1953:
And here is an I frame of the same vintage, pre Mod of 1953:
ColbyBruce
Member
I did not intend to mislead anything, being a poor, underpaid federal employee I can't afford a first edition J frame, LOL!! Seriously, I think I have only held two and owned one, 20+ years ago.
Your numbers aren't even close to what I've measured. Are you measuring the frame window/opening or are you measuring the distance from the recoil shield to the back of the barrel/forcing cone?
No. Frame window vertically and diameter of cyl. The dimensions for horizontal window opening and cylinder length between I and J are a 1/8" difference; the J frame being longer of course.
The vertical dimensions and cylinder diameters were to show that all I frames are not even the same as usually assumed.
Colby,
Didn't mean to sound critical. It's just that looking at different vintages of different models of these little jewels is what tends to confuse so many about the already confusing evolution of the various post war and '50s models.
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OP
Leslie Sapp
Member
Great info guys, thanks a bunch. There's a lot to digest here, but this will make a great thread to refer back to as I educate myself.
Well, keep in mind that the .32-20 HE is a K frame, not an I frame.
Jack
Added: Okay. I just reread your post and now understand what you were saying. Sorry for the goofy response.
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