Question on S&W frames and frame sizes

[nick]

Hi,

I'm not a revolver guy, I just carry one in the woods, but I want to learn more about them. So, here's my question.

S&W has various frame sizes. Are the frames within the same frame size dimensionally the same? For instance, would I be able to take a Model 66 frame and a Model 68 parts kit and put them together without modifying the frame (other than the usual fit and finish)? Or, say, a frame from Model 66 and a parts kit from Model 13? After all, these are all K frames. Ditto for S&W 586 and 686, both of which are L-frame.

Or do the frame sizes only refer to the frame type and the approximate size, but the frames for all the models within the frame size are dimensionally different?


Thanks,


nick

[redcliff]

While each frame size (J,K,L,N) is different in dimensions from each other all the models using that frame size have similar although not necesarily identical components. Due to production changes over the years different components may not interchange, such as early and late model hammers as early models have the firing pin on the hammer and late model ones have firing pin built mounted in the frame.

[nick]

While each frame size (J,K,L,N) is different in dimensions from each other all the models using that frame size have similar although not necesarily identical components. Due to production changes over the years different components may not interchange, such as early and late model hammers as early models have the firing pin on the hammer and late model ones have firing pin built mounted in the frame.

Thank you. Are there any other major differences? Are there major differences within the same period?

[redcliff]

Thank you. Are there any other major differences? Are there major differences within the same period?

I'm certainly not qualified to answer questions on the parts interchangeability between all models/eras of S&W revolvers.

However if you focus your questions to "will (part X) from a Model XX-whatever fit a Model xx-whatever someone may be able to help you.

[nick]

I'm certainly not qualified to answer questions on the parts interchangeability between all models/eras of S&W revolvers.

However if you focus your questions to "will (part X) from a Model XX-whatever fit a Model xx-whatever someone may be able to help you.

I will certainly get more answers that way, but I'm asking generic questions for a reason Before delving into what specific parts may interchange, I'm trying to figure out if one frame can be used for multiple models. Maybe I'm taking this too lightly, so I might end up researching what parts fit where, but I'm hoping it won't come to that just yet.

[dfletcher]

I will certainly get more answers that way, but I'm asking generic questions for a reason Before delving into what specific parts may interchange, I'm trying to figure out if one frame can be used for multiple models. Maybe I'm taking this too lightly, so I might end up researching what parts fit where, but I'm hoping it won't come to that just yet.

In general, the hammer and trigger of a K frame will fit all models of that frame size. For example, the trigger and hammer of a 13 will fit a 15, 14, 19, 10, 12 and so on. IIRC the hammer and trigger of a K frame will also fit the L and N frame too, but not the J frame. At some point I'm going to not be lazy and fit a target hammer/target trigger from my deceased Model 25 N frame into my K framed Model 14.

If one had a single action hammer for a K framed Model 14 they would be able to drop it into pretty much any modern K, L or N frame (again, staying "MIM to MIM" and "preMiIM" consistent) and have it function.

I know zero about the X frame.

There are exceptions - for example, a rimfire K frame hammer won't work in a centerfire model. The K framed Model 53 has a rim and centerfire feature on its hammer. And you should stay within the same period - don't put a 1970s made hammer/trigger into a 1930s made gun of the same frame. So far as I know, "pre-MIM" hammer & trigger and other parts will not work with current "MIM" guns. So staying "MIM to MIM" consistent is important too.

And generally some fitting of parts is required for best function.

Mainsprings, trigger rebound unit, hands and cylinder bolts for K & N are the same.

That's my short overview, of which many "yes, but you forgot to mention ....." exceptions probably apply.

[nick]

In general, the hammer and trigger of a K frame will fit all models of that frame size. For example, the trigger and hammer of a 13 will fit a 15, 14, 19, 10, 12 and so on. IIRC the hammer and trigger of a K frame will also fit the L and N frame too, but not the J frame. At some point I'm going to not be lazy and fit a target hammer/target trigger from my deceased Model 25 N frame into my K framed Model 14.

If one had a single action hammer for a K framed Model 14 they would be able to drop it into pretty much any modern K, L or N frame (again, staying "MIM to MIM" and "preMiIM" consistent) and have it function.

I know zero about the X frame.

There are exceptions - for example, a rimfire K frame hammer won't work in a centerfire model. The K framed Model 53 has a rim and centerfire feature on its hammer. And you should stay within the same period - don't put a 1970s made hammer/trigger into a 1930s made gun of the same frame. So far as I know, "pre-MIM" hammer & trigger and other parts will not work with current "MIM" guns. So staying "MIM to MIM" consistent is important too.

And generally some fitting of parts is required for best function.

Mainsprings, trigger rebound unit, hands and cylinder bolts for K & N are the same.

That's my short overview, of which many "yes, but you forgot to mention ....." exceptions probably apply.

Thank you! What about the cylinder sizes (are they roughly the same and fit into the same frame?) and holes/threads for installing the barrel?

[dfletcher]

Thank you! What about the cylinder sizes (are they roughly the same and fit into the same frame?) and holes/threads for installing the barrel?

Each frame size has a different cylinder size. Within each frame size, in general, the cylinders are the same size although there are exceptions. A 45 ACP cylinder is shorter than 357, 41, 10mm & 44 caliber cylinders for the same N frame revolver.

I tend to think threading of the barrel to frame is specific to each frame size, but not caliber specific. Also, sometime around 1980 Smith went from a threaded & pinned barrels to crush fit, so there may be a difference between threading size/type during those times.

[BigRich]

The triggers are the same for K,L and N frames. The hammers change length. Generally, the internals for a Model 13 will fit and work pretty well in any centerfire K frame if they are in the same generation. Once you get to the firing pin change taking place then this no longer applies.

[nick]

Each frame size has a different cylinder size. Within each frame size, in general, the cylinders are the same size although there are exceptions. A 45 ACP cylinder is shorter than 357, 41, 10mm & 44 caliber cylinders for the same N frame revolver.

So the frame for the .45 ACP cylinder would have different dimensions, right?

I tend to think threading of the barrel to frame is specific to each frame size, but not caliber specific. Also, sometime around 1980 Smith went from a threaded & pinned barrels to crush fit, so there may be a difference between threading size/type during those times.

Hmm, this is something I'll need to test then. Buying parts as we speak

[nick]

The triggers are the same for K,L and N frames. The hammers change length. Generally, the internals for a Model 13 will fit and work pretty well in any centerfire K frame if they are in the same generation. Once you get to the firing pin change taking place then this no longer applies.

Thank you. So far I'm mostly looking at the older types, with the firing pin still in the hammer. This project will be fun

[dfletcher]

So the frame for the .45 ACP cylinder would have different dimensions, right?

No, the frame is the same size & dimension. Again, doing this from memory but the barrel protruding into the cylinder opening of the frame is a bit longer on the 45 ACP Model 25. I'd have to check to be certain, but I believe that's the case. Peeked at auctions on GB to double check.

I recall during the mid 70's, when Smith wasn't making a 44 Special, that folks used to convert their Model 28s to 44 Special. I'm pretty sure the conversion was done with an old "Model 24" barrel and cylinder, or by boring out the 28"s 357 chambers to 44 Special.

[BigRich]

The 45ACP cylinders are shorter to minimize bullet jump/freebore which can diminish accuracy. The barrel root/forcing cone area is lengthened into the frame opening to account for this.

[ldivinag]

my 2.75" barrelled 500ES is an X frame...

having a hard time finding a kydex holster. seems like the X is the red headed step child... lol...