I just disassembled my 627-5 to cold blue part of the hammer and trigger after some custom work had been done. It's the only MIM gun I own and I have disassembled and reassembled it a few times. This time, however, I could not get the hammer to lift after reassembly. After walking away to compose myself, I returned to take a second and more thorough look at it. It looks like the sear is not fitting properly and I believe I lost something. A tiny spring, perhaps? The sear is loose, and I'm guessing I lost a spring which fits into the tiny hole in the MIM sear. Am I correct? I do not have and can not find a schematic for these parts. I guess I can order one from Brownell's? Is this part the same among N Frames with MIM parts?

Dave Sinko

SEAR SPRING, MIM HAMMER - Brownells

What is MIM, have seen it on parts disc. Second ? how hard is it to change Hammer and Trigger that are Blue to Chrome in 4506, or have parts chromed. Thanks

I figured as much but the Brownell's schematic is for forged parts that are pinned. Why is it so hard to find a schematic for the MIM guns? I bought this gun used without any literature and I still can't find a diagram for a MIM gun. I'm trying to love and appreciate MIM but this is definitely a huge setback.

Don't know much about a 4506 either...

Dave Sinko

I don't know if this will help or not, but the most current S&W Parts Catalog, which I got from S&W in Feb of this year, only lists one Sear Spring Pt. No. for the 627 Model(s).

It's 0702
There are a bunch of zero's after those four numbers but I have ordered quite a few parts direct from S&W this year and those are the only ones they use.

I did some checking regarding the N & L Frame Sear Spring part numbers and came up with this.

The M686 used the 0702 spring up until the -5 designation.
After that, no. 21577 is listed as the Sear Spring pt. no.

The M29 also used the 0702 S.S. until the -7, the M27 used the 0702 S.S. until the -9 & the 629 used the same 0702 S.S. until the -5 designation.

After that, all of the above switched over to the 21577 pt. no., like the 686-5 mentioned earlier.

Based on that, if you give S&W a call @ 800-331-0852 and have the two part numbers listed above handy they should be able to fix you up, if you can't find what you're looking for anywhere else.

As I mentioned, I've ordered quite a few parts, direct, lately and have had good service throughout.

The price for each spring should be less than a dollar, so shipping would be more than the part itself.

__________________
Ogy

There are two springs: the forged hammer spring 0702 and the MIM hammer spring 21577. The guns had forged parts up to a certain point in time then (mostly) became MIM. Some like the 627 were after the "MIM transition" but had MIM or forged hammers depending, apparently, on what S&W had "on hand" during the production run or chose to use. It was considered a "feature" on some "MIM" PC N frames to have a forged, pinned sear, FMFP hammer.

This is a perfect example of where "ya gotta be carefull". A 686-4 should be "pre MIM" and a 686-5 should be MIM but you see both -4 and -5's with varying combinations of parts specific to each. You see -4's with the -5 pinned sight barrels, -5's with the -4 integral sight barrel, etc.

The only thing that seems certain is the 686-4 or earlier is HMFP with a forged hammer and the -5 up are FMFP with an MIM hammer. I don't believe there is an K/L frame forged, pinned sear, FMFP hammer as there is for the N frames.

Kudos to tomcatt51. Same thing happened to me today upon reassembling a 637-2.
Ordered several today from Brownells.
Could NOT find a parts diagram for that revolver.

That seer spring is the smallest damned spring I think I've ever seen. Was taking down and cleaning a 642 airweight, looked down and just HAPPENED to glimpse a TINY spring. Luckily I was able to figure out where it went and place it back in its proper spot. Such a tiny and important piece. It should be painted dayglo orange