I found a super clean 4506. The trigger is stainless but the hammer is black. Does that mean it is MIM?

Seems like the MIM ones always have a black hammer and trigger.

If so, is it easy to to get another SS hammer? Is it an easy job for a 'smith to replace?

Thanks

Non-MIM hammers and triggers were made crome plated to look like stainless in earilier production, and just like with the revolvers, the flash crome plating of hammers and triggers ended in the early to middle 1990s a few years before MIM parts were used. If your blued hammer is not hollowed out on both sides of its spurr it is not MIM. I have not owned a 3rd. gen. auto with MIM parts. I think non-MIM and MIM hammers interchange but thats a question for Fastbolt or another member. Changing hammers and triggers is easy. It probably is easier to find a blued trigger to make the colors match.

I hope this helps a little.
Gil

Yep, the flash-chromed hammers and triggers started going away in the mid-to-late 90's as the MIM parts were being produced.

The older machined hammers were also made available in black for some models.

I don't pretend to have anything like a definitive answer, but here's some hammers I grabbed out of my parts bins.

The 2 hammers on the left (spurless) are both machined carbon steel hammers. The flash-chromed hammer is for an early production 3rd gen 6906. Notice it has some serrations at the top. The black finish spurless hammer next to it is newer and listed as a part for one of the later production Value Line guns. It lacks the serrations on top.

The 2 hammers on the right are both MIM. You can see the indentations in the sides which indicate it's a MIM part.



Now, the triggers can be a little interesting. I've seen a bit of variance in the machining & finish of the older machined triggers, in the area of the "prongs" (or hooks) which ride in the V-notch of the drawbar head. The MIM triggers have always seemed to be much smoother and more uniformly shaped in that area.

The older machined hammers could have anywhere from a very smooth to a very rough surface on the rounded front surface, depending on the sharpness of the cutter used when it was made. The MIM hammers are uniformly smooth. (Something you might notice in a DA trigger stroke.)

The 9/.40 triggers were also a bit wider in the models which had wide frames (for double column mags), compared to say, a 3913. The MIM triggers were narrower across the face than the older machined triggers in the wide frames guns, and had a slightly rounded, higher center instead of being as flat across the face as the older machined triggers. I had mixed feelings about the slightly narrower and rounded face MIM triggers ... until I'd invested a lot of range time with them in a 59XX gun. Then I decided I liked them. Quite a bit.

I can't remember comparing the older .45 triggers (4516 v. 645/4506), though.

While I've heard conflicting info from factory sources (including in different armorer classes) about mixing machined & MIM hammers and sears in TDA guns, for the sake of optimal long term functioning, when it comes to matching hammers & sears I'd keep MIM with MIM and machined with machined. (In DAO guns it's absolutely required to keep machined/machined & MIM/MIM when it comes to matching hammers and sears. There are distinct angle differences between the old and new DAO parts.)

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Ret LE Firearms inst & armorer

Now that was damn informative. Thank you.Being a revolver guy I'm fairly new to semi auto pistols. Specifically 3rd gen S&W's. I've purchased 4 in the last 10 months. Anyway, I've seen a lot of chatter about MIM parts and I'm curious as to weather or not I should be considering switching out the MIM parts on a couple of the guns I have for Stainless parts? If so,where would be the best place to find them?

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I reckon so

Having spent some years supporting S&W 3rd gen guns as an armorer (and carrying one or another issued and personally-owned models & calibers for 20 years), I've come to actually prefer the MIM parts over the older machined carbon steel parts.

The first time I handled & dry-fired a stock 5906 with MIM parts, I thought it had received a trigger job compared to my early production 5903 with machined parts.

Finding the older flash-chromed hammers & triggers is becoming harder to do. One of the problems is that since they aren't making new flash-chromed hammers & triggers, most of what you might find is going to be a used part.

I've switched out older machined parts for MIM parts in some of the guns I've used, including my duty guns.

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Ret LE Firearms inst & armorer

Thanks, good to know because I have a 4506 in excellent condition that I picked up that has a MIM hammer and trigger and I rather like how the trigger feels and shoots. I also have a 3913TSW pre rail with a bobbed hammer and I believe it is also a MIM part along with the trigger. Both MIM triggers on these guns are smooth and crisp

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I reckon so

If you (like me) prefer the flash chromed triggers & hammers, if you end up with blued pieces you can send them to Armalloy. Their hard chroming is absolutley identical to what Smith used to do.


Cat

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Think for yourself.