Model 39-2 slide on a 439 frame?

[Joss House]

I tried my model 59 slide on my 439 frame but it was a no go. I'm curious if I purchased a model 39-2 frame assembly would it be compatible on my 439 frame or is there some internal modifications necessary?

 

[JohnHL]

The models 39-2 and 59 share the same slide assembly.

John

 

[Green Frog]

I'm not an gunsmith nor do I play one on TV, but there are two spring loaded buttons that go through the top of the second and third generation slides to operate the various levers below.The first gen slides have only one... that in and of itself would make the swap not work. I don't know whether it would be practical or even possible to alter a first gen slide to do the work of a later one, but there are enough 2nd and 3rd gen slides out there, that it probably wouldn't be economical, IMHO.

Froggie

 

[squidsix]

The firing pin block is not present on a 39-2. It is present on the 439. The 39-2 has a half-cock notch to catch the hammer if the sear fails. The 439 does not.
So yes, you could remove the firing pin block from a 439 slide and put it on the 39-2. It would not be safe the other way around.

 

[Green Frog]

Don't ask why, but the question has bubbled up again. Would it be practical to rework a slide from a 39/59 to simply take the second plunger (for the FP block) and use it on a second or third generation lower? It seems like adding that second plunger and spring would be all that was needed to update the first gen slides for later guns. Am I missing something critical here?

Froggie

 

[stansdds]

The firing pin block is not present on a 39-2. It is present on the 439. The 39-2 has a half-cock notch to catch the hammer if the sear fails. The 439 does not.
So yes, you could remove the firing pin block from a 439 slide and put it on the 39-2. It would not be safe the other way around.

The second pistols do have a half-cock notch on the hammer, at least my early production 439 does. The half-cock notch was deleted for the 3rd gen pistols, perhaps some of the late production second gen pistols came without the half-cock notch.

 

[stansdds]

Don't ask why, but the question has bubbled up again. Would it be practical to rework a slide from a 39/59 to simply take the second plunger (for the FP block) and use it on a second or third generation lower? It seems like adding that second plunger and spring would be all that was needed to update the first gen slides for later guns. Am I missing something critical here?

Froggie

The slide would have to be machined for the extra plunger and spring and I expect the firing pins are different, but I'm not sure about the firing pin. The question is, why put a first gen slide on a second gen receiver, especially when both slides are the same length? If it's for a windage adjustable rear sight, trust me, they were not all that great.

 

[JohnHL]

Don't ask why, but the question has bubbled up again. Would it be practical to rework a slide from a 39/59 to simply take the second plunger (for the FP block) and use it on a second or third generation lower? It seems like adding that second plunger and spring would be all that was needed to update the first gen slides for later guns. Am I missing something critical here?

Froggie

As Member stansdds has pointed out, machining the slide to accept the firing pin safety apparatus would allow the a 1st gen slide to work on a 2nd/3rd gen frame.

Also, modifying the firing pin safety apparatus in the frame of a 2nd/3rd gen frame would allow the use of a 1st gen slide, but then you would be eliminating the firing pin safety which would make the pistol NOT "drop safe".

In response to your question, I tried a nickel 39-2 slide (w/windage adjustable lollypop sight) on my 2nd gen 659 (Same action as 639).

It fit but would not function because the 1st gen 39-2 slide has no accommodation for the firing pin safety lever on the 2nd gen frame.

The trigger would stop as the firing pin safety lever raised up and hit the slide.

It would be possible to grind on a firing pin safety lever and neuter it in to a "spacer" and then it would work.

I've never been crazy about removing safety features but that's the nuts and bolts of the conversion and if you ever decide to do it, now you know how.

John[/QUOTE]

 

[Green Frog]

So, after reading this, I’m thinking that simply boring the hole for the second plunger and the Gen 1 slide makes it work as a Gen 2 upper, right? From what I’m seeing, it looks like a simple, straight hole that could be drilled down from the top (I would do this precisely on a mill) but no taper, shoulder or other complication to make it difficult, right?

I only ask this at this point because there seem to be a fair number of Model 39/59 slides floating around cheap, and if somebody :roll eyes: wanted to have a more useful spare slide...

Froggie

 

[JohnHL]

That should work, assuming someone really wanted to put a 1st gen slide on a 2nd or 3rd gen pistol and have a firing pin safety.

And they would still a 2nd/3rd gen firing pin along with the safety plunger and spring.

But I love the academic exercise.

John

 

[Green Frog]

OK John, here’s another academic exercise... how about a Model 915 slide on a 2nd Gen frame? It Should work as it looks like the 915 is to the rest of the 3rd Gens as a Model 28 revolver is to a Model 27. They only came with fixed sights and single sided decocker, but otherwise look like they are the same. Do the internals interchange? I’ve read the appropriate section of SCSW, 4th ed, and that’s what I got out of it.

Froggie

 

[JohnHL]

915 slide on a 2nd gen frame is a GO.

Mechanically, 915 is identical with all 2nd and 3rd gen, standard 9mm slides, with the exception of 908/9/10, CS, TSW, and PC pistols.

Different rail configurations on those excepted models.

John