642 Airweight Help

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Hi, new here. I bought a new 642 S&W Airweight and proceeded to install a spring kit. I removed the hammer assembly and a small black metal part fell out of the hammer group (it mates and pivots with the hammer). It looks like there should be a small spring and possibly a post that keep the two pieces together. I didn't notice anything fall out, but I must have lost something because the gun doesn't function correctly now. Does anyone know what part or parts I might be missing? There are no gunsmiths within driving distance. Thanks.
 
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If you are talking about the small black piece that links the end of the mainspring to the hammer (on earlier revolvers that is pinned in place and called the stirrup), it can go into the hammer two ways, but only one is correct without limited motion that will block the hammer throw. If it is the sear, that sits in a cutout on the forward part of the hammer with a small spring behind it. It also was pinned on the earlier guns.

Stu
 
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This is why I buy Maintenance Manuals for anything Mechanical. In addition after reading up on a Procedure if its beyond my skill set it goes to a Gunsmith.
 
Without photos it sounds as if the sear fell out. I don’t know about the mim hammer but the pin that holds it in on the forged hammers has to be driven in.

There is a spring under the sear in the hammer face.
 
Then, after the gun is correctly reassembled with the new "updated" low powered springs, the gun will no longer fire reliably. So then a longer firing pin will be installed. After it still will not fire reliably, the original springs will be re-installed, and the gun will work again. SUCCESS!!! :)
 
If you are talking about the small black piece that links the end of the mainspring to the hammer (on earlier revolvers that is pinned in place and called the stirrup), it can go into the hammer two ways, but only one is correct without limited motion that will block the hammer throw. If it is the sear, that sits in a cutout on the forward part of the hammer with a small spring behind it. It also was pinned on the earlier guns.

Stu

Thanks Stu, I believe it's the sear that sits in the cutout of the hammer. The small spring is gone to where ever small springs and screws go when you drop them. I never actually saw the spring, but you can see where it should be. It's a new 642 Airweight but I can't seem to find a part number. I'm wondering if it's just a spring, or if there is a plunger or pin involved. When I try to look up a schematic for this gun, all I get is a generic S&W parts diagram with a different design. If anyone can help me with a part number, I can probably fix the mess that I created. Like I said, there are no gunsmiths within driving distance from me, and with the current travel restrictions, I'd like to do it myself. Thanks to all for responding.
 
Then, after the gun is correctly reassembled with the new "updated" low powered springs, the gun will no longer fire reliably. So then a longer firing pin will be installed. After it still will not fire reliably, the original springs will be re-installed, and the gun will work again. SUCCESS!!! :)

X2........I've NEVER replaced a spring.......I wear "em" in by shooting them.
Have saw lots of post with parts change problems as you mentioned above.
 
Hi, new here. I bought a new 642 S&W Airweight and proceeded to install a spring kit. I removed the hammer assembly and a small black metal part fell out of the hammer group (it mates and pivots with the hammer). It looks like there should be a small spring and possibly a post that keep the two pieces together. I didn't notice anything fall out, but I must have lost something because the gun doesn't function correctly now. Does anyone know what part or parts I might be missing? There are no gunsmiths within driving distance. Thanks.

See this thread: 642 sear spring

I believe this is the part you might be missing:

SMITH & WESSON SEAR SPRING, MIM HAMMER | Brownells

A while back I noticed, when I had one of my airweights apart, that it had a kinked sear spring, so I ordered several of the sear springs (because you don't want to order just one!).

If I recall correctly, the sear is held in tension by the spring. You need something small and thin to press the spring into a little hole, and then slide in the sear. I think I used a heavy sewing needle.

You'll figure it out, it's not too hard. (Sometimes I think the people that design guns have three hands, but that's another issue).
 
Re: Replacing springs. Some times the S&W springs are extra heavy. I use the Wolff standard power hammer spring on them(both J and others). I have not had misfires with the standard power springs, I have to use Federal primers on guns that have the reduced power hammer springs in them. I have 2 642 revolvers. The first one is fine with the original S&W spring in it. I bought a 2nd 642 (new but no lock) it was very heavy, put the Wolff Std in it and now it's about the same as the first gun. I see the same problem with the guns that have the flat spring in them. Quality seems to be hit and miss even with S&W these days. I just bought a 626, not only a real heavy hammer spring but the trigger hangs at the beginning of the double action pull, when it finally pulls thru I pull the trigger all the way thru. Will tear into it one day soon and see if it's something I can take care of or if I have to send it back. Irks Me to No End!
 
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Good God People!
Don’t buy a gun and start modifying it!
Buy a gun and shoot it!

I don't exactly disagree on this, but I have a different perspective.

My view is that a man's got to know his limitations. And some work is best done by a professional. But life is too short to shoot stock guns.
 
Good God People!
Don’t buy a gun and start modifying it!
Buy a gun and shoot it!

Exactly!

Once you've shot it enough to run in and mate the internals you'll know pretty much if ANY modifications are needed.

A NIB 1911 is my favorite example, Series70 natch. There is a world of difference between that very first shot and that same pistol after 500 rnds of hardball have been sent down range.

Rob
 
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I removed the hammer assembly and a small black metal part fell out of the hammer group (it mates and pivots with the hammer).

Not to be rude but. . . . if you don't know the names of the parts, should you be taking your gun apart?

That said, I know the names of parts but I've lost more parts than I can count. My basement is littered with tiny parts that have flown away, never to be seen for years. Losing parts is part of working on stuff.

If you plan on doing more tinkering, get a copy of Jerry Kuhnhausen's "Smith and Wesson Shop Manual."
 

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