I have noticed the general dislike of revolvers with MIM parts - buyers looking for guns specify no MIM.

Are the MIM parts prone to failure? Or is this just a perceived lower value part?

I opened up a 617-4 MIM revolver that I recently purchased.



I felt the parts were much better fitting than previous vintage S&W revolvers I have worked to smooth the action of.

The 617-4 may get a new spring, but, I was impressed with how smooth the gun generally functions. I always wondered how S&W got the 10 shot to "time" properly. I think S&W would have a hard time getting the finish and repeat-ability of MIM parts with machined components, especially at this price point.

I doubt they could get a 10 holer to time as correctly, without MIM. Of course, that is just MHO!!

I can not count how many 6-holers I passed up after finding during cocking the cylinder did not "lock up". This 617 10-holer does that perfectly.

Will somebody help me understand MIM value, function, and performance??

I owned a Model 625-6 for a while that had MIM guts. That one had a great action. Very smooth from the factory.

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Centennial Every Day

MIM parts don't look as nice as color casehardened parts, and some say the forged parts are easier to smooth and tune. In all other respects they are superior -- and, yes, that means they are less expensive to make, among other things. Something wrong with that? Not to me.

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Pisgah

Most of us are just anal about such things.
f.t.

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South Carolina-God's country

Buyers are disappointed when they buy a gun, & it's put together with cheaper parts than it used to be. When I can lay out a bunch of Sig 226's, & you can see the German made ones from the 80's have milled parts, & the newer ones have cast, or mim parts, it means Sig wanted to save money to keep costs down. Sure the parts won't last as long, but they'll probably outlive the barrel. Arsenal AK trigger parts used to be forged. [milled] Now they're mim parts. That's why I replace my AK cast, or mim trigger parts with Chinese milled parts. Most of my pistols I fire 100 rds a year, so in my case it probably wouldn't matter, but to some, [myself included] newer isn't always better. GARY

I think it's a general fear of technology and, therefore automation.
Haven't you seen The Terminator. One day, the computers will make all the MIM parts and guns they need to wage war on mankind.

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Hold on. SWAT's at my door.

Perception is everything. Forged and machined parts mean greater attention to detail and hands on care during the manufacture of fine firearms. MIM means a faster, cheaper, lazier if you will, way to manufacture a firearm. Both perceptions, whether true or not, it's the way people see it.

For many, the thought of a classic firearm being made by any other process than forging and machining parts from solid steel is sacrilegious. It's just the way we are.

That stinking hole in the side on the other hand.

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SFC, US Army, Retired

Personally, I don't really have a problem with the MIM parts (unlike my feelings about the IL, but that is another well-beaten dead horse). But if I were offered a MIM or a forged S&W, with all other factors being equal, I would take the forged one every time because the perceived value (and therefore future resale value) is higher with collectors.

Someone said that newer isn't always better, true, but the implication is that it is always worse. Not true. Think about this, with their life time warranty, S&W does not want to institute a new process just because it is cheaper, if it does not result in a longer trouble free life for the product. Warranty work is expensive, very expensive. Even with modern CNC machining systems, the process is subject to errors. Tools wear, the machines wear and things change. And the idea that just because there are machining marks on a part, it doesn't mean that someone took care and gave extra effort. Computers don't care, they just follow preprogrammed instructions.

The only S&W revolver I have with MIM parts is a Model 57 Mountain Gun. I like it well enough. What gets me is the sound of the action. Cock it, or pull the trigger double action and it sounds like a cheap cap gun. Do the same with an earlier all forged parts action and it sounds solid. Just my perception, I like the sound and feel of the older actions much better.

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Copyright MCMLXII ©

Show some reliably documented evidence that S&Ws MIM parts won't last as long as milled or forged. You won't because you can't. S&W wouldn't be fitting MIM parts if they weren't reliable and durable. Don

Each and every MIM equipped S&W revolver that I have owned has had just as smooth (or smoother) action as any non MIM revolver that I own. I do think that I can tell a difference in the sound of the action. I have a model 60-12 that has MIM parts but no lock, and I'm OK with that. However, like it or not, it does make a difference in the value of the revolver.

Perceptions can be warped by emotions.
Less expensive is not always lower quality.

In my case, and this is my own perception, both work - but - the specter of catastrophic failure is greater with MIM.

I realize both types fail and I realize both types are dependable, what I am saying is that the potential for a void leading to failure exists with MIM and when this happens the part crumbles, breaks, lets go.

Forged is less subject to this due to the process of manufacture, but that's not to say it can't fail.

I've had non firearm MIM failure and I recall my days of youth with metal parts of toys failing and seeing the crystalline composition inside and I can't shake that image when I think of MIM.

I know this is not germane to current MIM, but none the less it makes me shun MIM.

I think that fear breakage is the underlying reason. I don't know if that fear is real or not, but a lot of 1911 guys really make a big deal of it. The purists deride the "MIMber" 1911s because Kimber is known to use MIM parts. The perception is that MIM parts are cheap and therefore unreliable.

BTW, I have a 10 shot M17 that I really like. I shoot it better DA than I do most of my SA pistols.

Vern

So why didn't S&W just rivet MIM firing pins into MIM hammers? Why the complete transition to frame mounted firing pins across the entire revolver lineup?

And what is the bottom line in savings per individual revolver? Is it pennies? Dollars? Tens of dollars?

Dave Sinko

I think the dislike comes simply from the fact that most of the MIM-haters are older guys like me and you know how much us olde pharts hate change. If it is not made the way "it used to be," it's bad.

I spent my working life in the automobile industry as a dealership master technician and then service manager. When we got the first computer-controlled fuel and ignition systems in the mid-70s, they were nightmares to diagnose - and there were plenty of problems to diagnose. But as the years passed, the manufacturers got a better handle on electronic controls and the result is the smooth, powerful yet economical engines we have today. But getting there caused a lot of gray hair!

MIM parts are being received the same way those of us in the automotive field received those electronic controls. It's new and it's different, so it sucks. But in time, it also will be accepted.

All my S&Ws are non-MIM, non-IL guns. I felt that I will always be able to buy MIM/IL guns, so I ought to get the old ones while they are still available in nice condition. I own one MIM gun, a Kimber Stainless Gold Match II in .45ACP. On that gun, I don't mind the MIM parts because they look just like the forged ones on my older 1911s. There is no hollow back on the trigger and the hammer is shaped exactly the same as a forged hammer. And there is no lock.

I guess it's a case of out of sight, out of mind. Or what I can't see can't hurt me.

Ed

I don't know what percentage of MIM parts are in the Smiths, but I would not be concerned as long as those installed parts weren't parts subjected to stress or fatigue. I can live with MIM, not with the clinton hole.

In my non-technical opinion, there is no fundamental problem with the metal injection molding process. It is cost effective. It works when executed correctly and used for parts that aren't stressed more than MIM can handle.

The quality control problems come in when the accountants and marketing execs get together and decide on a price point for gun X. Then they ask "How can we make the gross margin as big as humanly possible for gun X?" And they push the engineers to use as much MIM as possible and to push the envelope on how to use it, especially in terms of quality control procedures.

I don't like the MIM part because the tend to be kind of ugly externally. I like flash chromed and color case hardened parts.

Functionally I haven't had a problem with MIM or forged parts. Maybe I need to shoot more and report back later.

Emotionally I think its kind of sad to see guns that have been produced for decades or longer in the case of the 1911, with forged and machined parts transition to MIM parts.

This.

I had a catastrophic failure of a Para pistol when the extractor broke. Para engineers came up with a brilliant idea for an extractor, the 4-piece "Power Extractor," then some numbnuts (bean counter, I assume) decided to make it of MIM, turning a great idea into a negative.

Have to weigh in on this.
Presently, I have 36 S&W revolvers with an age span of about 70 years. Newest ones are MIM ones without IL. All of these are fired regularly, some a lot, some less.
In 40+ years of shooting S&W revolvers, I have experienced exactly one catastrophic parts failure. Guess what? It was a FORGED part that broke, not a MIM one.
The bolt on my Model 60 (purchased new in the early 1970s) broke. Locked the gun up tight as a tick:

Luckily, this breakdown didn't happen during some social encounter in the mountains of southern Arizona (my old stomping grounds).
The revolvers I shoot the most have had their actions smoothed and tuned.
My experience is that the MIM parts are made so smoothly that little, if any, additional polishing is ever required. Tolerances are closer, as a rule, giving a more solid feel to the weapon, especially when opening and closing the cylinder.

...my $0.03, YMMV

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-jwk-
US Army '72-'95

MIM parts are fine. I've never had, nor heard firsthand, of one single issue.

I have guns with plastic (or whatever they want call it) parts. I did have a plastic part break on a new Ruger. Even then, they fixed it immediatly and for free. So I don't have an issue with those either.

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But then, what do I know?

This thread subject should be made into a sticky and locked like the ILS thread.:banghead:

Sent from my DROID RAZR MAXX using Tapatalk 2

Nice to see someone else in my neck of the woods, I spend a lot of time in roanoke.
As for the MIM parts I have never had any problem with my modern revolvers.
I do prefer the old ones but for mostly aesthetic reasons.

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27-2, 66-1, 640 Pro, 10-5

Absolutely correct. Don

I think the answer is that the hammer mounted firing pins won't pass the drop tests some states, CA to be sure, require. That seems like a good idea so that they can continue selling their guns. Don

Is the hammer block not supposed to prevent the revolver from firing when dropped? I have heard that it is the length of the fame mounted firing pin that caused some revolvers to fail the CA drop test. When they shortened the frame mounted firing pin to compensate for this, the result was problematic ignition in certain revolvers, such as the 625. Some shooters will correct this with aftermarket extended firing pins. This would mean that many shooters now have revolvers that are no longer compliant per S&W's original intentions.

And is the frame mounted firing pin MIM or forged?

Dave Sinko

" I recall my days of youth with metal parts of toys failing and seeing the crystalline composition inside and I can't shake that image when I think of MIM."


Yes, but, the toys of which you speak were of CAST construction....and probably cheap "pot metal" at that....NOT M.I.M. That is a very different process.

Yes, voids can occur with MIM, but actually that is quite rare.

I do NOT bring this up to criticize anyone. Everyone is entitled to his/ her perceptions, likes and dislikes - and no one is "wrong" for having them.

I just wanted to try to dispel any associations people may have with MIM being equivalent to "cast". It most definitely isn't - it is a far superior process.

The firing pin should be bar stock, which would be far cheaper than MIM or forged.

Those 2 processes are for "shaped" parts like a trigger.

IMHO

Well I'm old so most people would think I hate MIM parts and I don't as long as they are the right parts and in the revolver for the right reasons. If they are there where they shouldn't be for just most cost cutting purposes then I don't want them.

Like others have said I hate the IL because it was never needed and a complete surrender by S&W to the Government.

MIM is currently used mostly as a cost cutting measure that should have no effect on performance. True or not, it is here to stay. Now, should I avoid any new pistol just because of MIM parts? Guess I can't because there are some nice new models I want to own. I would pesonally perfer that all pistol parts were made of forging, but that's not going to happen. Sometimes you be be able to replace the MIM parts out with forged parts. But MIM will not go away, that's for sure.

Frame mounted firing pins are Ti and are WAAAAAAY better than hammer mounted when it comes to getting trigger pull down, they can go lower.

I like well done MIM, S&W does it right. It only take 5 minutes to do a trigger job as far as polishing goes, no more cutting new sears to length etc. S&W MIM is just wicked evil hard.

From an economic standpoint it may be cheaper to produce the physical part, but the initial tooling costs are really high.

The main problem with MIM is the name.

If MIM was called "Cold Forged Injected Colour Case Hardened Alloy with Big Hammers" I really think it would have been more accepted by Smith and Wesson purists.



From my own experience, my MIM 686 has been sublime. I also like the dirty look to it as well.

To be quite frank, if it wasn't for the internet I would never have heard of MIM..or penguin porn for that matter.

As suggested above, it's mostly just a question of perception and a concern over potentially diminished quality. MIM parts can break (though sometimes only if you force them to), and the broken surface looks a little like fine-grain pot metal. Not an encouraging sight.

I have never had a problem with a MIM part and can attest that the actions on my guns that have them are among the smoothest have experienced. If I didn't know the phrase or have to look at their rather drab appearance, I would not have any negative judgment on them at all.

But despite my approval, I have to confess I would rather have precision milled carbon steel or stainless parts in the action. If it was good enough for grandpan's guns, it's good enough for me.

Don't much care for polycarbonate frames, either, but I know most of them work out just fine.

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David Wilson

Most guys equate the differences of MIM vs. forged to the automoblie industry...back in the hot rod days of the 60's and early 70's the performance cars sported a forged steel crankshaft instead of the usual cast iron crank found in the stock engines. Since forged car parts are more valuble and cost more it must be that a forged gun part has to beat a MIM one {makes sense to most guys.} Both methods have their good and bad. I have seen plenty of cracked and wrung off forged steel crankshafts in my 16 year previous career as an automotive machinist so forged steel is not a cure all. Since forged parts are hot stamped metal they do have somewhat of an "alignment" of the molecules and kind of take on a grain all going the same direction. In many cases that gives the part the strength it needs to last. In example, connecting rods in engines have been forged steel for a very long time, even in stock non-performance type engines. MIM on the other hand is very fine atomized metal "powder" that is heated and pressed into shape. This has several advantages...the crystalline structure of the molecules dampen and cancel out vibration and its associated fatigue so the service life can be much longer. It is easier to MIM form much harder alloys than it is to forge and then machine so you can get a much longer wearing part. How long do you want it to wear??? Just add some tungsten carbide dust. I think alot of guys see a broken MIM part at some point and note that the appearance looks like a very clean sudden break, as if the part just let go and didn't even try to hang on; as opposed to a forging that often cracks in a small area and continues to work for a while until it finally gives in.

MIM parts don't have the tensile strength of machined steel parts.

Nothing wrong with MIM parts other than the looks. If they could just make them look as good as the forged parts with their beautiful case hardened colors.

My take on the reason frame mounted firing pins (FMFPs) were used rather than hammer-noses were that FMFPs were already used for the rimfire guns - much simpler to use the same parts across the entire line of products* (the hammer noses were different shapes between J, K, L, and N-frames).

I believe it's easier to put a firing pin into a frame than it is to put one into a hammer, and then have to make sure the tolerances are such to allow that hammer assembly to be used in a frame.

I also believe that having a FMFP also reduces the likelihood that a firing pin hole could get elongated or misshaped by repeated cycles of the action.

*The MIM K- and L-frame hammers are also the same part. I *think* the MIM N- and Z-frame (Governor) hammers are the same part (I know for sure the hand is the same between the N- and Z-frame). The K/L/N sears and stirrups were and are all the same part; the K/L/N trigger rebound slides and trigger assemblies were all the same, along with their springs, the mainsprings, etc. So having similar parts across the line helps keep costs down.

Yes S+W started using MIM parts to cut the cost down...... Yea for them. They sure as hell don't pass the saving on to us. Let's face it forged parts are better. You can fool yourself into thinking there the same or better but there not. If they are the same or better why don't they use them in there more expensive P.C. guns?

You have an advanced materials science degree? If you don't you're probably not qualified to state that with conviction.

Ever consider that S&W might put forged parts in place of MIM on PC models just to satisfy the PERCEPTION that forged is better than MIM to please the part of their audience that hates change?? Don

I had a conversation today with a S&W firearms engineer I know. I brought up the issue of frame mounted firing pins saying one of the big reasons for using them was passing drop tests. He said yes.

Regarding 2-piece barrels, another feature many dislike. Again, it's there to reduce stress on the barrel and the frame interface. Good reasons for both design features. Don

Yo Don ease up a little. I didn't say I hated MIM parts I even own a couple guns with them. It's just one man opinion on the subject. If you want to keep drinking the cool aid smith & wesson is poring thats up to you. When they go from MIM to plastic lets see if you feel the same way. Oh by the way about the plastic thing I also own a S + W M+P shield and  a Glock love them both. 
Take care.
Mike  

That doesn't make sense to me. The frame-mounted pin is susceptible to inertial movement (gun stops, pin continues forward). The hammer mounted one isn't because the hammer block prevents it.

Unless I misunderstand the lockwork...?

There are LOTS of people on this forum with far more knowledge of the internals of S&W revolvers than I have. In the case of the frame mounted firing pins, I'm just reporting what the engineer said. He was a big player in the development of the Model 500. Don

We need a physics professor to chime in to answer this one.

The frame mounted pin is so small, it has a tiny amount of mass.

For that tiny mass to be effected by velocity, the gun would need a WHOLE LOT of velocity.

At that velocity, slowing down fast enough to make the firing pin move enough to set off a round in the chamber, I would bet the gun becomes the projectile doing the damage,

forget about the bullet!!

IMHO

Tradition and emotion are ... tradition and emotion. The fact is that the FMFP and MIM parts are an improvement. We don't have to like it. But there it is. It's not unlike the outrage of those who so adored the 1903 rifle. Yes the early rifles were made beyond the level of quality required for a service rifle. They were beautiful. But, the realities of WWI demonstrated the weaknesses of the design. In WWII, Remington improved the design with the 1903-A3. Purist hated it for being not as finely finished, etc. But there was no denying that it was an improvement especially in stocking, sighting and use of a one-piece trigger guard/magazine. The only reason anyone ever made parts by forging/milling was because the ability to make MIM parts did not exist. Colt once made SSA's w/ HMFP's. Ruger came along and took an idea from H&R and produced a better SA revolver, with a FMFP. It has proved outstandingly successful. One other thought about MIM... I may be wrong, but if I remember correctly, many of the critical internal engine parts in modern Jet motors are made by the MIM process. How many millions of people daily fly in planes which depend on such MIM parts to keep them all in the air?

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<><

What a pile of false dichotomy. The 1903-A3 was better, so MIM is better ?!?!

No, his point was that the 03A3 where often looked down upon because the barrel bands, butt plate, trigger guard, and rear sight where stamped, not milled, and therefore of "lesser quality". Only in the last ten years or so have the 03A3’s started to gain in popularity, especially with the rise in CMP bolt actions matches, because they are easier to shoot accurately, mainly in the rapid fire stage.
Reason for not liking MIM parts have been how it looks or how the gun sounds when it is cocked. Almost everyone sheepishly admits that the action is smoother than forged.
ALL of my S&W revolvers are pre MIM and IL. As of yet, I haven’t seen a new revolver that I have to have. The IL turns me off more than the MIM.

I'll be one of the first people to admit I hate them purely for the aesthetics. Frankly, I just don't think they look as nice as forged case hardened parts, and I can't stand hollowed out or scalloped triggers and hammers with sprue marks. If they were cosmetically identical to their older forged counterparts, I'd probably pay them no heed.

FWIW, back when I wanted to get rid of my Glock because it was just "too much gun," I -almost- ordered a brand new, NIL 442 Centennial. Seeing a circa '71 Chief's Special in my LGS's display case for a comparable price made me rethink that decision.

Buy whatever you want, but I still opine that traditional S&W revolvers better fit the description of "an elegant weapon for a more civilized age."