Back in early April I posted some rookie questions about my pawn shop find Model 639 with the ambidextrous safety. I got so much help and info from members JohnHL, jsbethel, Jeppo, Froggie and others that I was able to prove to myself that everything was OK with that gun, even though it was missing the right side ambi safety lever and the screw.

We have been enjoying and shooting the heck out of the 639 and my 39-2 simply because I have a heck of a lot more 9mm ammo than 45 acp (which the Model 745 eats).

So now only one thing remains to be found. I did get hold of a stainless steel right side ambi LEVER (the last one Numrich had in stock) due in this Friday, BUT the screw is nowhere to be found. I've tried flea-bay, Jack First, and several other sources but nothing original available.

The screw really appears to be Phillips Pan Head stainless steel machine screw and I'm sure I can get one from many sources IF...IF...BIG IF: I can get a technical description, or even basic dimensions (diameter and length) and most important, the number of threads per inch. With S&W being American made I doubt the screw is metric. It APPEARS similar to a Military Standard MS 51957-47 but that is only pictorially.

On the off chance that any member reading this may have a Model 639 with ambi safety and they HAVE NOT Loctited the screw in place...please measure thread diameter and length with calipers and let me know. If you a pitch gauge that would be wonderful, if not I can start with length and diameter.

Of course the gun is entirely usable as is, I simply would like to have it as it left the factory back when. Just me and my OCD on small things.

Moderators: If this post belongs in smithing please move.

Attached Images

	Mod 639 left side.jpg (60.4 KB, 35 views)
	Mod 639 right side.jpg (68.3 KB, 44 views)
	Mod 745 right.jpg (75.4 KB, 33 views)
	Ambi safety lever.jpg (34.2 KB, 39 views)
	Ambi safety screw ss.jpg (27.5 KB, 28 views)

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Charlie B
SWCA#3083, SWHF#570

There is a screw available from Home Depot that can be cut down and works well.

Sharing my finished 645,woes and fixes.

https://www.homedepot.com/p/Everbilt...1288/204225813

Heads up!

The screw version has a problem - the screw comes loose and it falls apart.

Try to find the version which has the dovetail slide on lever with a "Pin Retainer" I got a complete ambi. safety, both sides and slide on right with pin retainer. for my Model 39-2 from Numric for $60 several months ago.

They are out there and just take a little searching.

Attached Images

Ambi M39.jpg (187.2 KB, 29 views)

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Who are? "They"

Very common problem. My solution came from “The big orange home improvement chain”.

639 decocker lever screw

http://smith-wessonforum.com/attachm...9&d=1512770146

Numrich shows the ambi safety screw is in stock, $3.52 ea.

I honestly hate those ambi safeties on my CCW guns because they stick out so far on the side that prints under your shirt.
Interesting that none of my three Performance center compacts have an ambi safety.
If I can find a single sided safety I would swap it into my 6906 immediately.

I can't swear to it, but I've been told that the 2nd Gen single side safety will work in a 3rd Gen. Numrich has some and of course if it doesn't work, you can always return it.

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Can open, worms everywhere.

I've got a spare ambi screw, Charlie B.

PM me with your contact info and I'll send it to you.

John

OK......Thanks to the generosity of Member JohnHL my Model 639 is finally looking just like it did in June 1983 when it left the factory.

John was gracious enough to send me not one, but two factory ambi safety lever screws, the Phillips head style.

Looking back with always 20/20 hindsight, I'm thinking that S&W probably could have abated the screw shooting loose if they had made that a left hand thread which would then tend to tighten as the slide slams back with recoil.

Due to the notorious shooting loose, I'll probably just leave the ambi lever and screw at home when hitting the range, but it is nice to have the gun back in original configuration.

Thanks again John and if I can do something for you..please PM.

Attached Images

	Mod 639 right side.jpg (68.3 KB, 17 views)
	Mod 639 factory Phillips safety screw.jpg (67.1 KB, 20 views)
	Mod 639 original safety screw.jpg (98.2 KB, 25 views)

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Charlie B
SWCA#3083, SWHF#570

cmansguns,
The original prototype ambidextrous safety for the Model 39 same as the one for the 439, simply used the standard stock screw for the model 39/59 to retain the lever.Did you try a stock screw? The phillips head screw looks wrong on a gun in so many ways! Very few guns have ever used phillips screws. If you ask nicely I might tell you about the original ambi safety.

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Gunsmithing since 1961

Charlie, I'm tickled that they finally showed up!

When I dropped them off at the PO on 6/23, the nice lady gave me a receipt indicating an expected delivery of 6/27.

When more than a week had passed without their arrival, I became concerned that they had fallen into a USPS "black hole" only to surface again at some undisclosed time and place.

I first shot a 2nd gen with the phillips screw attached ambi safety lever back in the '80s (a 659), before the advent of the 3rd gens with their significant improvement in lever attachment.

In all these years of shooting 2nd gens, I've never lost one of the screws (and I know you haven't, either), but I've also been aware of the problem and checked the screws frequently.

Even though I am right handed, I've always liked the ambi safety and practice left handed, just in case.

I didn't like the looks and attachment with the screw, and I have tried several options including loc-tite, split ring and belleville lock washers, single side safeties, 3rd gen safeties, and even complete 3rd gen slides.

They all worked, but the wisest and most practical solution I can think of is yours:

My pleasure, Charlie!

Your gracious acknowledgement combined with the satisfaction of seeing your 639 complete is more than enough for me.

John