637-1 ?

[Johnnu2]

Does my 637-1 Airweight have an MIM hammer and trigger?

Thanks,
J.

 

[saemetric]

Good question. My trigger doesn’t look mim but hammer might be.

 

[CAJUNLAWYER]

Hold it up to the computer a little closer so I can see.
The one in the second picture has both MIM hammer and Trigger

 

[Johnnu2]

What second picture...?
IIRC I didn't post any picture....But I will post 2 pics now....below.s. I bobbed the hammer so it will be difficult to tell by viewing, but the trigger is quite visible...Yes, the grips are incorrect... they are for 'pocket carry'.
I guess the question still is the same: "Does a 637-1 have an MIM hammer and/or trigger by virtue of it's 'dash/DOM'?".

 

[mikerjf]

Look at the back of the trigger. If there's a recess or "trench" in the back, it's MIM. If not, it's forged.

AFAIK all non-hammer-nose hammers are MIM.

 

[Johnnu2]

Thanks for your thoughts mikerjf. The back of my trigger has no trench but it has a CCH coloring that looks exactly like a 'trench' that was filled in. I'm the original owner so I know it's never been touched-up. So, who knows (?). The hammer does not have an external firing pin on it. I may just write to S&W some day.
J.

 

[Coastie762]

The hammer is MIM. In your photo of the bobbed hammer you will see a mould seam running down the back.

Nice job on the hammer bob.

 

[Johnnu2]

Coastie..... I think that line that you see running down the middle of the bobbed hammer is actually a shadow form my lousy lighting. p.s. one of the reasons I asked about MIM or not is because I read somewhere on the Forum that MIM hammer and triggers need factory/gunsmith fitting while non-mim hammers/trigger can just drop in. In the case of my bobbed hammer, I had purchased that hammer as a spare in case I screwed-up the 'bobbing'. Not knowing any better, I installed it and it functions perfectly. I've had it like that for several years and have even taken it out to the range in mid-winter weather, left it on the bench for hours and then tested it to be sure it would fire 100% despite that lighter-weight of the modified hammer. So far, so good, although I do admit that I do not practice with my SD gun ever so the number of rounds through the modified hammer is less than 50. So, that's my story..... thanks to those who've responded with their thoughts.
J.

 

[mod34]

My current understanding is that just because it - the trigger - doesn't have the "groove" doesn't necessarily mean its not MIM.

 

[Coastie762]

I'm attaching a couple of photos to show the difference between a forged and MIM J-frame hammer. You can take a look at the original hammer from your gun to compare.

A forged hammer has the double action sear pinned to the hammer. The DA sear on a MIM hammer is not pinned. The interface between the hammer and mainspring strut is also different between the two.

The mould seam on the back of the hammer I referred to is shown in the second photo. Some are more pronounced than others. I took another look at the photo of your bobbed hammer and still see it.

Please review and let me know what you think.

 

[Johnnu2]

Thanks Coastie.... I'll go an pull the side plate later today and let you know what I find.... I took another look at the hammer in my pic AND on the gun 'live'; it does appear to have the seam you're talking about. Thanks again,
J.

 

[Johnnu2]

Well Coastie, I didn't have to pull the side plate to confirm the hammer (and most assuredly the trigger) of my 637-1 are MIM parts.... I went and found the original hammer that came with my gun and it matches your picture. Here is a pic of mine that I just took:

As mention in prev note, I had pulled the original and 'bobbed' a spare that I had bought just in case I messed up the bobbing job. yup MIM and it fit right into my gun with no fitting necessary.
Anyway, THANKS for your help....
J.

 

[Coastie762]

You're very welcome! Regarding the trigger, on your gun that may well be forged. The 637-1 came along in that transitional period between introduction of MIM parts in the late 90s to the -2 revision introduced in 2002.

When you swapped hammers do you recall if the rod that connects the trigger to the rebound slide was pinned to the trigger or separate? Forged triggers used pins to retain the rod and also the sear spring. MIM triggers do not, they are also hollow in the back, forged ones are flat.

The attached photo shows a forged trigger from a model 60. Next to it is a rebound rod that fits into a MIM J-frame trigger (I didn't have a J-frame trigger lying around). Hope this helps!

 

[Johnnu2]

Looks like I'm gonna pull that side plate after all .
I don't remember how that rod was connected to the rebound slide, although I'm pretty sure that it must have been pinned because I think I would have noticed if it was just "fit in". But it's been several years since I had it apart.... will take a look today (I have absolutely nothing else to do).
AND HERE IT IS..... it appears to me that the rod going to the rebound slide is on a pin (?) Y/N ?



If I must, I can still pull it apart further, but it's such a PIA to put that rebound spring back in there (even with the proper tool).
THANKS AGAIN,
J

 

[Coastie762]

No need, trigger is definitely forged. Interesting mix of parts!

 

[Johnnu2]

Thanks Coastie.... appreciate it...

p.s. I used to do weekend reserve duty in LaCrosse, Wis. when I lived in Mn. back in the 70's....

Adios for now,
J.