Model 39 and 59 slide interchangeability?

rlee1976

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Hi. I just purchased a nice Model 59 (I'll post pics when I take delivery on it) with a nickel frame and blue slide. Could this be a factory finish? Anyway I digress... What I really want to know is if a slide for a model 39 will work on the 59 frame. I could possibly pick up a nickel slide that came off a model 39 and I thought it would be fun to see my gun in all nickel. Thanks for your help. Also the serial is A174***, anyone know the date of mfg.? Thanks.
 
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I don't think S&W made any two tone model 59's, either someone had the frame nickeled or swapped the slide, which gets to your other question, the 39 and 59 do use the same slide. In fact, the slides from the 2nd gen pistols will also fit.
 
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yes... the entire top ends are the same, basically the only difference between the 39/59 is the wider grip frame size to fit the double stack magazine and longer hammer and sear pins on the 59.

There is a caveat I forgot to mention, I know there is a difference in the extractor between the early and later model editions... what I'm not sure about is when the firing pin safety was introduced and whether or not a slide with a firing pin safety will work with an older frame without the actuating lever, unless the firing pin safety is removed from the slide.
 
Neither the Model 39 nor the Model 59 has a firing pin safety. Those came with the next generation of semi-automatic (M639/M659, etc.). Such a Second Generation slide would not work on the earlier frame since there would be no mechanism to disengage the firing pin safety. The long extractor on the early M39 pistols will not affect the interchangeability of the slide assemblies, but it would not make sense to swap to the more-prone-to-failure long extractor.
 
Are you sure your frame is nickel? Could it be that someone has removed the black finish and you are seeing polished aluminum?
 
No, it's nickel. It's a pretty cool looking gun. Here's a pic from the auction.
 

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Judge Colt, so if I'm understanding you correctly, the extractor on the model 39 is more prone to failure? Also if anyone can tell me, being new to guns with a decocker, how can the 59 have an accidental discharge if dropped, like I've heard? Is that just if the hammer is cocked? Not if it's decocked, right? Because the hammer would be blocked then. Thanks fellas.
 
Our Model .59 in nickel...

Here is my son's .59 that was given to him on his 17th birthday by my father (retired LEO). It is a nice looking and shooting gun!
I think it's an alloy, not really nickel, but I'm not sure...
 

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Wow, what a sharp-looking gun! The frame is alloy, the slide is steel, but the whole gun is nickel-plated. Thanks for the pic!
Ryan
 
Without a firing pin safety to keep it from moving forward until the trigger is pulled, it is possible if dropped in just the right way, that it could move forward under inertia and hit the primer hard enough to set it off, regardless if the hammer is blocked by the decocker.

The extractor on all M39's aren't prone to failure, it's just the early ones, which are easy to distinguish. They are wider and longer than the later ones. On the outside of the slide if it goes from the decocker to the ejection port, it is one of the early extractors.

P.S. that's a nice looking pistol you have there, I used to have a nickel 459 until I sold it off for a Glock... stupid, stupid... stupid!
 
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When was the firing pin safety added to these model 59s? Also the 39s if someone knows; I'm thinking about picking up one of those as well. Also if someone could enlighten me as to how the decocker functions on these guns? Like I said this will be my first experience with a gun with a decocker. Does it simply lower the hammer and make the first shot DA, or does it also act as a manual safety in some way? Thanks.
 
Since you're familiar with revolvers, when you have the hammer cocked and locked, what do you do when you want to decock it?

Put your thumb on the hammer, pull the trigger and slowly lower the hammer down with your thumb?

That's basically what the decocker does in addition to blocking the falling hammer from contacting the firing pin after it's released.

As long as the decocker lever is down, the trigger is disconnected and the gun can't be cocked by pulling the trigger. Also if you pull the hammer back it won't stay cocked either, so the decocker does function as a safety too. Flip the lever up and then the first shot on a 39/59 can be double action, like a revolver, by pulling the trigger to cock the hammer and fire the gun, or you can pull the hammer back to cock the pistol and then pull the trigger to fire... single action.

The firing pin safety appeared on the second generation pistols, which have a 3 digit model number (i.e. 439/459).

In my opinion not having a firing pin safety on a 39/59 is not such a big deal, I didn't let it discourage me from getting a M39-2 or owning a pre Series 80 Colt 1911.
 
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Gunhacker, perfect answer! Thank you kindly sir. Do you know then what the difference was between the model 59 and the 59-2? I thought that it was the firing pin safety, but like you said that was the 459. Also, exactly what does that firing pin safety that they added to the 459 do/how does it work? Thanks.
 
Best way to describe a firing pin safety is imagine a round firing pin with a notch cut into it that a spring loaded plunger fits into to block any movement of the firing pin.

The end of the plunger extends down from the underside of the slide so a lever in the frame can push up on it to disengage it from the firing pin as the trigger is being pulled and just before the trigger releases the hammer, allowing the firing pin to move when struck.

Releasing the trigger moves the lever down and allows the plunger to lock the firing pin again.

That is basically the way it works on most makes of pistols with a firing pin/striker safety.

I'm not up to speed on exactly what all of the changes were made with the -2 models. The ones I do remember were mainly in the slide. New extractor style, on the 39-2 the profile of the barrel feed ramp was changed to improve the feeding of hollow point bullets, the recoil spring guide rod changed to a smaller diameter.

I think there were other cosmetic changes like the length and/or shape of the decocker lever, slide release lever, and the rear sight became adjustable for elevation and windage, instead windage only. The magazine followers and base plate made a change too.

That's as much as I can remember on the modifications. Also, S&W did not waste anything, so whenever an engineering change occurred, it was not uncommon for S&W to first use up old style parts on the newer version.

These were called "transitional" guns and both revolvers and pistols experienced it where there was a short period of time when old and new met because it was not a cut and dry switch over when changes were made.

One example is the style of the ambidextrous decocker lever on the 2nd gen pistol carrying over to some of the early made 3rd gen pistols, that eventually changed to the newer style that's not attached with a screw, after the older style stuff was used up.

Another example is on the 3rd gen 4506. There are some frames stamped 4506 that have the newer features of the 4506-1... S&W just used up the old frames on hand with the different shaped trigger guard, and didn't bother to re-stamp them to 4506-1.
 
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Thanks again for the clear, succinct answer. I knew about those changes in the 39-2 (i.e. the feeding ramp and the extractor), but maybe the change in the 59-2 was the barrel bushing? I heard they switched to some sort of "half-moon" barrel bushing in the 59-2? I wonder what the reason for this was?
Ryan
 
The older style barrel bushing has a closed loop that the guide rod passes through, they lopped off the lower part of it so it's now a 1/2 moon shape just like a Colt barrel bushing. I'd guess it was to eliminate any binding taking place between the bushing and rod? The new style carried over to the 2nd gen pistol.

My 39-2 has the older style bushing and there's an area near the end of the recoil spring rod that looks like a squirrel has been chewing on it... I don't know if it's the product of the older bushing or from the rod being aluminum.
 
Judge Colt, so if I'm understanding you correctly, the extractor on the model 39 is more prone to failure? Also if anyone can tell me, being new to guns with a decocker, how can the 59 have an accidental discharge if dropped, like I've heard? Is that just if the hammer is cocked? Not if it's decocked, right? Because the hammer would be blocked then. Thanks fellas.

I see that your questions have already been addressed, but some clarification is needed.

As stated, an inertia firing pin can develop enough energy if dropped on the muzzle "just right" to ignite the primer. The M39/M59 firing pin is prevented from moving if the safety is engaged, but not if the safety is not engaged. The firing pin safety on Second Generation and later guns prevents movement of the firing pin until the trigger is pulled.

There is a nomenclature issue here that illustrates how important it is to be accurate in nomenclature. The Model 39 and the Model 39-2 do not use the same style of extractor. The Model 39 has the long extractor, which is more prone to breakage than the short extractor found on the Model 39-2. While sometimes a general reference to a "Model 39" is sufficient, it is not when discussing changes that resulted in a new model number being assigned.

The Model 39 and the early Model 39-2 both used a two-piece barrel bushing. The "flat part" sitting vertically against the front end of the slide is a stamped, separate piece from the cylinder-like portion of the bushing that goes around the barrel. The two are attached together by "rolling" the front edge of the cylindrical part into the hole in the flat part. Some (most?) of those two-piece bushings separate, allowing the recoil spring to escape, which puts the gun out of service. (The early Model 59 used the same two-piece bushing with the same problem.)

The "fix" is the cast one-piece barrel bushing, which can easily be identified by the lack of a hole at the bottom for the recoil spring guide rod. I do not believe eliminating the hole had nothing to do with "binding" on the guide rod. There just is no need for the hole in the cast part, so it was eliminated. (The half-round configuration "straddling" the guide rod is sufficient to keep the bushing from turning, which was the purpose of the hole in the original stamped two-piece part.) No "dash-number" change was made when the one-piece bushing was introduced on either the Model 39-2 or Model 59.

There was never any "Model 59-2." The nomenclature was "Model 59" throughout production. The Model 39-2 nomenclature was solely to identify the change in the extractor style. As stated, the change to the one-piece barrel bushing did not result in a new "dash number" for either the Model 39 or the Model 59.
 
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