3900/6900 slide information

[daffyfellow]

Hello everyone,
I picked up this slide many years ago. I recently tried it on multiple 3rd generation frames and have noticed that the rear of the slide rails are cut differently from all my other slides.
This results in about 1/8" of frame rails showing.
The slides features make me believe it is an older design.
It has the early sights. Front sight black. Rear sight grey.
It has a narrow barrel hood.
It originally came with ambidextrous safety levers.
The roll marks seem to be older also.
It is the same length down the middle but the back of the slide seems to have been domed over.
I took some pics next to a newer Novak sight 6906 slide.

Has anyone ever experienced a slide with this milling?
Is the rear of the frame on the pistol it's on also rounded or domed?
Do you think this may have been manufactured around the time when S&W was transitioning from three digit to four digit pistols?

Thanks for your time and attention.

 

[1775usmarine]

Im no expert but going to say the slide is a 2nd gen slide.

 

[Green Frog]

There were some adjustments going on with the slide specs at S&W in those times... there was also the "Value Series" that had some third gen, some second gen, and some unique features (as I have just found to my chagrin and expense. ). When I put a 439 slide on my 639, the rear of the rails marched, but I was told at the time there was no guarantee that this would be the case.

You state that it came with ambi safety... was it old style (screw on right lever) or the later style wth pin and spring lever retainer? That might help pin down its vintage.

It seems to me the exact history of the changes in second and third gen S&W semi auto pistols could stand some serious research and explanation!

Froggie

 

[jsbethel]

Do you think this may have been manufactured around the time when S&W was transitioning from three digit to four digit pistols?

It is an early 6906 slide - I have a complete upper with the same rounded design.

 

[daffyfellow]

The slide came with the typical third generation ambidextrous safety lever.
I didn't think it was second generation because the front sight is adjustable in a dovetail.
Ok so early 6906.
I suppose the rails of the early 6906 are shorter so they match up.
Thanks for the replies.

 

[4T5GUY]

I am NOT an "expert" by a long shot but can factually say that there are, (were,) at least three different slide lengths/configurations.

I said all of this here before. The 669 now 6906 I got for nothing had the rear sight, (old style,) busted off. There was not any replacements available at the time. No big deal cause I wanted Novak's anyway I would just get a complete top end. It was a big deal as it turned out. The first complete top end fit AND functioned fine but it was too long and hung over just enough to bother me. The second complete top end I got fit AND functioned fine but was too short just enough to bother me. I eventually got a NOS rear sight and replaced the broken one on the original top end.

I parted out the shorter one and the longer one, (Novak's,) is perfect on my 3906 and 5906. It's fun running it on them and it's a viable option.

Jim

 

[stansdds]

I'd say there were five different slide lengths/configurations for the compact 9mm pistols.
469/669.
6904/6906 with the small rear sight.
6904/6906 with the Novak rear sight.
6944/6946 DAO with the rear of the slide extended to conceal the hammer.
CS9 Chief's Special 3 inch barrel.

Yours appears to be the early 6906 slide with the small, 2nd gen style rear sight, but dovetailed front sight. There is a fairly high degree of variation with dimensions, so slide swapping often results in a mismatch between the rear of the slide and the rear of the receiver rails. Even on factory pistols there is often a small mismatch.

 

[Sevens]

Look at the picture in Jim's post #6. I have no inside info but I think the evidence I've seen suggests that the 2nd/3rd question is simple.

If it has the four lines of S&W info, it's a 2nd Gen slide. Integral front sight means 2nd Gen while dovetail front and four lines of info means leftover 2nd Gen slide that has been upgraded with a dovetailed sight to be used on early 3rd Gens.

No four lines? 3rd Gen slide.

Jim's pictures shows them nicely.

 

[daffyfellow]

Look at the picture in Jim's post #6. I have no inside info but I think the evidence I've seen suggests that the 2nd/3rd question is simple.

If it has the four lines of S&W info, it's a 2nd Gen slide. Integral front sight means 2nd Gen while dovetail front and four lines of info means leftover 2nd Gen slide that has been upgraded with a dovetailed sight to be used on early 3rd Gens.

No four lines? 3rd Gen slide.

Jim's pictures shows them nicely.

The second generation slide would also have the ambidextrous safety lever with a bolt on the right side.

 

[Sevens]

But those are just parts in the slide — not the slide. Early 2nd Gen slides had no lever on the right side.

 

[daffyfellow]

New evidence.
Just got a blued 6904/3914 slide with Novak sights.
It has the same roll marks as the early stainless third gen slide that started this question.
It also has the rounded over cuts on the back of the slide.

So I think the roll marks are a good indication that slide will be a bit short on the rails.