MIM vs. Machined

[mec]

I don't much think Smith will go out of business tomorrow. Back in the 70s, the then-owner suggested a federal licensing program for gun owners. Customers rebelled and deserted them in droves. Later, another owner buddied up with the Clintons- same thing. Over the last fifty or sixty years, customers have greeted one money-saving change or deletion or lapse in quality control after another with howls of protest accepting each in turn after something worse came along. There is no consequence for alienating one customer base when another comes along to take its place and the company does not seem to be hurting for sales.

Fortunately for those of us who like the more traditional revolvers, we are a deminishing lot and the supply of fairly-nice to near-new older revolvers seems adequate to meet the demand.

 

[sharpshot71]

I find it funny that this discussion went from the likelyhood of MIM parts breaking to the fact that the purists are angry that S&W is using no longer using forged parts.

It would appear from most of the responses on this site that people's issues with MIM do not really come from the process itself, but mostly from S&W making a lower quality gun for more money. The two are entirely unrelated.

Just like anything else, without proper quality control or implementation, ALL process suck, and will make junk parts. If a company replaces a forged part directly with a MIM part it will likely fail. Designing a part to be made with any process demands an understanding of the process and what the material properties are. MIM parts likely do not have the same properties as forged parts, so as drop in replacements, they may fail. A part properly designed to be made using MIM likely won't fail.

That being said, some processes have inherent weak aspects. eg. cast parts are very brittle. Therefore they CANNOT be used in some applications. If a manufacturer uses a process in the wrong application, don't blame the process, blame the manufacturer.

You also realize that adjusting sear engagement and rehardening the affected surfaces is rather common practice in trigger/action jobs, right?

If it was hardened in the first place, it can be cut and rehardened. If it was not hardened in the first place, it can be cut with no need to reharden.

Drop the price, ditch the lock and I can live with the MIM parts.

It would appear Craig is more angry at S&W, not so much at MIM parts.

 

[Shane Tuttle]

It would appear Craig is more angry at S&W, not so much at MIM parts.

S&W happens to be on the radar for use of an example. Seems to me people get their undies in a bunch when this happens and thinks it's turning to a bashfest....

 

[gyvel]

I think I know what disposable means. There's no time constraint on "used once". You don't throw away a disposable cigarette lighter after using it one time, do you?

Not the best example. A "disposable" lighter is made to be used until a finite amount of flammable gas is used up, and then disposed of as it is not designed to be refilled.

Forged parts can be, and often are repaired when other new parts are not available and "originality" is paramount. Good examples would be welding and repairing the lever on an 1860 Henry rifle, or building up the sear and half-cock notches on an original 1873 Colt SAA. You can't do that on a MIM part.

But, all that said, my only complaint so far with MIM parts is that they look like cheesy, cast pot metal parts in the S&W revolvers. I haven't had my "new 1917" long enough or put enough rounds through it to make a determination of longevity of the MIM parts.

One thing that does really suck, however, is the fact that the hammer in that particular model can't be replaced with a forged part since I am unaware of any older N frame revolvers that carry the firing pin in the frame

 

[CraigC]

If it was hardened in the first place, it can be cut and rehardened. If it was not hardened in the first place, it can be cut with no need to reharden.

If you had read the thread, you would've seen that MIM parts are created in the desired hardness but they cannot be hardened after the fact. Nor can they be welded.

It would appear Craig is more angry at S&W, not so much at MIM parts.

I'm not angry at anyone, nor are my drawers in a bunch. I'm merely explaining why S&W will not get my money for a current production gun. You may not agree with it or think there is any merit to my position but it is what it is. I cannot pay more for less, period.

Forged parts can be, and often are repaired when other new parts are not available and "originality" is paramount. Good examples would be welding and repairing the lever on an 1860 Henry rifle, or building up the sear and half-cock notches on an original 1873 Colt SAA. You can't do that on a MIM part.

Exactly!

The two are entirely unrelated.

The two are entirely related! A manufacturing process that's sole purpose is to lower manufacturing costs resulting in a lower quality product should equally lower prices.

If S&W goes out of business tomorrow someone will start making replacement parts at some point. Just like you can pretty much build a 69 camaro out of new reproduction parts.

Unless I'm mistaken, there are currently no sources of new replacement parts for the old guns. I know where to go to get replacement hammers and triggers for Old Model Ruger single actions (that are better than originals) but no such source exists for S&W parts.

 

[sharpshot71]

If it was hardened in the first place, it can be cut and rehardened. If it was not hardened in the first place, it can be cut with no need to reharden.

If you had read the thread, you would've seen that MIM parts are created in the desired hardness but they cannot be hardened after the fact. Nor can they be welded.

My point is that if a sear on a MIM part is recut, no part of the cutting process changes the hardness of the part, so the sear is STILL the same hardness, nothing has changed.

I have seen no mention that MIM has any type of case hardening effect. So ALL MATERIAL IS THE SAME HARDNESS on that part.

THEREFORE IF THE PART WAS NOT HARDENED IN THE FIRST PLACE, IT DOES NOT NEED TO BE HARDENED AFTER CUTTING!!!!!!!!!!!!!!!!!!!!!!!!!!

Read part in bold twice, because apparently you missed it the first time I posted it.

Yes it is true they cannot be welded(maybe, at least as told on this thread), but for the everyday user, that doesn't matter. And you can't blame any company for building a gun that has everything 99% of the buyers want. You are obviously not part of that 99%, so buy a gun from a maker that makes what you want.

 

[FrankenMauser]

MIM parts can be welded.

I've heard everything from it being like welding cast iron (a giant pain in the ***, that requires a lot of experience); to it not being bad at all.

Like everything else discussed in this thread; it seems to depend upon the part itself, and the method by which it was made.

Some parts described as "MIM" are not actually 'Metal'. They are improperly classified polymers, with metal particles in suspension. That is probably another factor that leads to misinformation. (And definitely precludes welding.)

 

[JohnKSa]

A manufacturing process that's sole purpose is to lower manufacturing costs resulting in a lower quality product should equally lower prices.

There are several things wrong with this statement.

1. The assumption that a process that lowers manufacturing costs automatically implies lower quality is not true. Lower manufacturing costs and less expensive processes don't always mean lower quality.

2. The idea that the sole purpose of MIM is to lower manufacturing costs is an assertion that has not been supported with fact. It's entirely possible that in some cases the proper use of high quality MIM parts may improve overall durability/fitness/quality of the part. An analogous situation is Caspian arms using cast frames, NOT because they were cheaper, but because they had fewer returns on the firearms they built on cast frames.

3. The assumption that lowering costs should automatically lower prices is simplistic. I've seen several specific cases where gun prices don't track inflation well---situations where the price of a particular new gun didn't change significantly over a period spanning a decade or more. If that's the case it means over time the profit margin erodes due to inflation unless the manufacturer can find ways to reduce cost. So it's entirely possible that manufacturer may be cutting costs to keep prices the SAME in spite of inflation. Or, depending on inflation, they may be cutting costs and may still have to increase their prices to keep a workable profit margin.

 

[Captain Nice]

I have just spent most of this day reading through this and other threads and have found some very intelligent and persuasive arguments both pro and con on the use of MIM parts in firearms. I am not an expert in metallurgy and would not attempt to offer an opinion one way or another. However I would like to offer my own personal experience. I own five S&W J and K frame revolvers, two of which contain MIM parts, a Model 60-14 with 2 1/8 inch barrel with the internal lock purchased new several years ago and a Model 66-5 with 3 1/4 inch barrel without the internal lock purchased used recently for a ridicules price, I just had to have it.

My experience was with the Model 60. It is my carry gun of preference when I carry a gun for protection which is rare as I live in a state where you will go straight to jail for defending yourself with a firearm no matter what the circumstances are. I had the gun down at the range several times firing 50 rounds of either .38 Spl. or .38+P ammo at each session. Although it is chambered for it, I have never fired .357 Mag. Loads through it. On this one occasion after having about two hundred plus rounds through it I noticed a very rough feeling to the trigger pull when firing double action. I have experienced two broken hammer pins on other Smiths that I’ve owned and thought that was the problem. I immediately stopped shooting, took the gun home and very carefully removed the side plate to inspect the action. I immediately noticed that the hammer block had broken in two near the base where the trigger pin slot is, that’s a lot better than a broken hammer pin. I am not sure if this is in fact a MIM part or a cast part. It is certainly not a machined or stamped part as it has mold lines and circular dimples in several places. The part is also non-ferrous as it will not stick to a magnet so my guess is it’s some kind cast pot metal. I replaced the side plate without the broken hammer block and of course the gun functions just as well without it. I believe this is the only internal part that the gun will continue to function without. I called Smith, explained the problem and ordered two replacement hammer blocks. If it broke once it will probably break again and I wanted a spare on hand. When I offered my credit card information for payment the gentleman on the other end of the line said it was Smith’s policy to replace this part free of charge. Great! no charge and I can replace it myself, that made me very happy. About a week later I received an envelope from Smith with the replacement parts. Upon opening the envelope I found two plastic envelops containing two hammer blocks each, however they were not the same. One envelope contained two hammer blocks that were exactly the same as my broken part PN 29631. The other envelope contained two hammer blocks, PN 22694, that were obviously stamped steel. The decision was now mine and I chose the stamped steel part over the MIM or cast part to place in my gun. Even though the part broke, I view this as a good experience with Smith, my choice of an original replacement part or a part that is better than the original and free of charge to boot. Smith obviously realized the error of their ways and corrected it. I would imagine that later production examples of the current Model 60 series have the stamped steel part.

As iterated over and over again in this thread, any part no matter how manufactured is subject to breaking, you just have to hope that it doesn’t happen at a critical time. I have a Colt stainless steel Python 4 inch in which the firing pin has broken twice and the main spring broken once, very disconcerting. I don’t think I would trust my life with this gun, it’s a safe queen now. I’ve seen them go for between $1,500 and $2,000 on Gun Broker, many times more than what I paid for it. I guess I’ll pass it on to my son and let him cash in on it if he wants to. I have had other non MIM parts break on my Smiths, Colts, High Standards, Walthers and others. If you fire them, sooner or later something is going to break.

I know this has been a little long winded for a first post, so thanks for reading it.

Once you eliminate the impossible, whatever remains, however improbable, must be the truth. Sherlock Holms

 

[JohnKSa]

The part is also non-ferrous as it will not stick to a magnet so my guess is it’s some kind cast pot metal.

There are commonly used ferrous alloys (particularly some stainless steels) that are only very weakly magnetic. It may be a cast or MIM part but I assure you that it is not made of "pot metal".

 

[Captain Nice]

There are commonly used ferrous alloys (particularly some stainless steels) that are only very weakly magnetic. It may be a cast or MIM part but I assure you that it is not made of "pot metal".

Okay, here are some clues as to what the composition of the metal might be. First off it looks like the part is either chrome or nickel plated. The top of the part that slides under the hammer is pretty well beat up and the underlying metal shows a reddish cooper color where the chrome or nickel is worn off. Under a magnifying glass, the cross section where the break occurred is rough with a look almost like a break in cast iron. I can also see specks of the same reddish cooper color in the cross section. It must be some kind of alloy that Granny Smith cooked up to make this part.


Once you eliminate the impossible, whatever remains, however improbable, must be the truth. --- Sherlock Holms

 

[Teuthis]

The real issue with firearm quality in this day is not the materiel, but quality control. If you have read this thread you will by now know that MIM parts are used in jet aircraft engines and other critical applications. Properly manufactured MIM parts have more than the strength required for firearms use.

The problem is that, for Smith and Wesson, compared to their former quality and care, they currently manufacture junk. Ruger is not, at times, far behind; And Colt is perhaps worse. The reliability of their products, which by virtue of being used for critical self defense use, is below the level that one can trust in a crisis.

I paid over $1000. for a Kimber 1911 45 ACP and just about the first thing it did was have piece fall off it to render it null and void. And it jammed too many times for me to trust it. I no longer own it.

Unless one pays thousands of dollars for a custom pistol, one can have no real confidence that American made firearms will perform as required, when required.

MIM is a minor issue compared to the overall, haphazard manufacturing quality, and reliability of modern, American firearms. What you are are experiencing with MIM parts breaking, is not an MIM issue. It is a quality control issue from companies who are now incompetent to produce the quality of firearms that we associate with those names.

I have no currently-manufactured handguns upon which I rely for self defense. They are all 25-30 years old. They have never failed, because when they were manufactured, they were of the highest quality possible. That feat now seems beyond the capabilities of modern, American firearms manufacturers.

 

[JohnKSa]

Once you eliminate the impossible, whatever remains, however improbable, must be the truth. --- Sherlock Holms

I agree with Mr. Holmes, but in this case "the impossible" is that the part is "pot metal".

I believe this is the only internal part that the gun will continue to function without.

Missed this earlier. Yes, it will function without it, but one should leave the chamber under the hammer empty if there is no hammer block installed.

 

[Captain Nice]

Missed this earlier. Yes, it will function without it, but one should leave the chamber under the hammer empty if there is no hammer block installed.

After replacing the side plate without the hammer block installed, I too was concerned about the missing safety component. Prior to loading the cylinder I checked for single and double action function, I also checked for forward movement of the hammer by pressing as hard as could on it and was surprised to see that it did not move. Correct me if wrong but when the hammer is in its rebounded position the sear sits just above the lifting surface of the trigger preventing forward movement of the hammer even without the hammer block in place. It is conceivable that if the gun were dropped on its hammer on a hard surface the sear could break and a discharge could occur. So Holms submits that due to the ingenious design of S&W’s double action mechanism, the hammer block is merely a backup safety feature. That said, I believe you are correct in stating that under the circumstances the chamber under the hammer should be empty, there is no such thing as being too safe when handling firearms.


Once you eliminate the impossible, whatever remains, however improbable, must be the truth. --- Sherlock Holms

 

[CraigC]

The assumption that a process that lowers manufacturing costs automatically implies lower quality is not true. Lower manufacturing costs and less expensive processes don't always mean lower quality.

John, you and I both know that S&W did not change the manufacturing process to make things better. They did so to lower production costs. I don't care if the parts are even better, they did it to reduce hand-fitting and labor. I really don't give a damn what process they use, if there is less handwork, it is of lesser quality. The best firearms in the world are hand-built, not mass-produced on machines. Handwork is expensive, reduce handwork and reduce production costs. This may sound very simplistic because it is very simple. In many ways S&W's guns have gotten cheaper, yet prices continue to climb. Maybe this is more perception than reality but remember, PERCEPTION IS EVERYTHING. By contrast, Ruger's guns have gotten better with the introduction of new CNC machinery, yet prices remain stable. They just go up like everything else. USFA continues to offer a superbly built and beautifully finished sixgun that is superior to a Colt that costs $400 more for around $750 street price. Even Colt has greatly improved their SAA and prices remain comparable to what they once were.

Cheap guns are made of cheap materials and cheap processes. Expensive guns are made of quality materials with stringent quality control and suitable manufacturing methods. It doesn't take a friggin' economics major to figure this out. Given that you own exactly zero S&W's, my assumption is that you have no dog in this fight and that your passion is for the argument itself, not the subject matter.

All this may lead someone to believe that I "hate" S&W and wish them put under. This could not be further from the truth, I wish them all the best and I hope they prosper. They're just not gonna do so with my money unless they change a few things. I'm a traditionalist and I'll gladly pay $900 for an older gun that gives me everything I want LOOOOOOOONG before I'll pay $900 for the new version that requires me to overlook a bunch of shortcomings to be satisfied.

 

[JohnKSa]

John, you and I both know that S&W did not change the manufacturing process to make things better. They did so to lower production costs.

I'm not arguing that lower costs aren't attractive to manufacturers, what I'm pointing out is that lower costs don't always automatically bring lower quality as your comment implies.

The Caspian example applies. I'm sure it costs them lest to supply cast frames in their guns but the user also benefits from a more durable gun in that particular case.

... if there is less handwork, it is of lesser quality.

Sorry Craig, I can't agree. You can't just go around redefining terms to match your opinion. Less handwork just means less handwork. Quality has to do with fitness for use, durability, reliability, etc. Assuming all those "features" still exist at the same levels or perhaps even at greater levels in the final product, saying it's lower quality because of a particular manufacturing technique doesn't wash.

Besides, there's a good argument to be made that handfitting is compensation for poor manufacturing techniques. After all, if parts could be popped out of a magic parts machine exactly the right size, shape and finish there would be no need for handfitting to get them to operate as they are intended to in the first place.

Even Colt has greatly improved their SAA and prices remain comparable to what they once were.

Then logic tells us that they MUST have reduced their costs--thereby, by your definition, reducing quality and making their guns "cheap".

Given that you own exactly zero S&W's, my assumption is that you have no dog in this fight and that your passion is for the argument itself, not the subject matter.

Actually, to the extent that I have a passion that relates to this discussion, it's probably a passion for accurate information.

What your argument is boiling down to is simply that you don't like MIM parts and you don't like guns with MIM parts. It makes no difference to you if they provide the same service life (or even better service life), whether they last as long or longer, whether they are as durable or even more durable. You just do not like them. I have no problem with that.

The problem is that you won't just say: "I don't like them!". Instead you say things like: "They are disposable." (insert personal definition of "disposable" here), "They are lower quality." (insert personal definition of "quality" here.) etc. Nothing triggers my "passion for accuracy", like opinion disguised as objective criticism.

 

[Jart]

...if there is less handwork, it is of lesser quality.

I'm having a hard time with this as well. While I'll concede up front that my sample size is small and I'm going by marketing claims only my STI Texican "untouched by human hands / ultra high speed 5-axis CNC" single action is noticeably more precise than my Turnbull/USFA "hand built by skilled craftsman" example.

I'll grant the Turnbull's bluing, or whatever it is, is marginally prettier but the STI is considerably smoother with a superior trigger. It manages to be tighter and slicker at the same time.

One thing in the Gunblast STI review that I can verify is that the STI's colored hammer doesn't pick up scratches from rubbing on the frame - quite unlike the Turnbull/USFA which is already pretty well worn. And the STI has seen far more rounds than the USFA.

If hand fitting is all that and a bag of chips, why can't they get the hammer in straight? I'm assuming the hammer issue is common among many firearms of that pattern - said assumption being based solely on the gunsmiths offering "hammer jeweling" options.

Realistically, I expect the STI to have more hand fitting than they claim and the USFA to have less than their marketing would have us believe. You and I watch the SAA threads - how long does it take for someone to chime in with the incorrect assertion that USFA is building the things under the blue dome? They haven't been there since 2003 and the move to the new facility was, according to at least one article, to accommodate the CNC machinery - which they have in abundance based on their website.

I think Mark Roberts of Colt's put it pretty well (as reported in 2006 on 1911 forum):

You may wonder with this level of hand building and checking how some of the quality issues that have popped up with Colt pistols could get out the door. I wondered the same thing, and Mark and I talked for a while on the subject. You see hand building can be a two edged sword, on the one hand you have the attention to detail and the ability to think and adapt to various situations that no CNC machine and assembly line will ever duplicate. On the other hand you are going to introduce a more subjective construction and inspection scheme. On a CNC machine it is easy to tell if something is in or out of tolerance, when a human being is grinding, or drilling, or polishing, or fitting a piece, their subjective decision as to where to stop is going to influence the tolerances of the finished piece. Sure micrometers, gauges, spec sheets and go/no go tolerances are used, and sure we as the buying public expect perfection for our hard earned money, but the bottom line is that products built by hand will have more variation than those built by machine.

Pretty interesting report - it's here if you're interested:
http://forums.1911forum.com/showthread.php?t=177275

It also touches on the "greying of the workforce". Hand fitting loses a lot of its luster if the hands are retired. I sometimes wonder if retiring craftsmen with the concurrent forced purchase of CNC mills wasn't suspiciously timed with the uptick in the SAA's QC. Conjecture on my part but I find it plausible conjecture.

 

[gyvel]

...if there is less handwork, it is of lesser quality.

I think what was being referred to here was "hand fitting" of parts which is often necessary to avoid problems caused by stacking tolerances when using so-called "one size fits all" parts, be they MIM, CNC, or whatever.

 

[Jart]

I think what was being referred to here was "hand fitting" of parts which is often necessary to avoid problems caused by stacking tolerances when using so-called "one size fits all" parts, be they MIM, CNC, or whatever.

Perhaps. I can't speak for the poster who said it.

Regardless, it remains opinion. The "hand fitting" of parts to reduce tolerance stacking is only needed when those parts weren't made to sufficiently exacting tolerances such that "worst case" tolerance stacking would still amount to piffle.

"Less hand fitting" means "less hand fitting".

One product employing a lot of hand fitting may operate better or worse than one with little hand fitting.

Correlation does not equal causation.

 

[CraigC]

It is a point of fact that the finest firearms ever produced on planet earth are/were hand-built. A $5000 Best Grade Bowen gun is built by hand, not stamped out on machinery. A $250,000 Purdey double is built by hand, not stamped on out machines. That much has not changed. Anyone who believes that the new mass-produced S&W's are better than hand-built Triple-Locks and Registered Magnums is delusional. THAT was my point.

The switch to MIM parts is purely to reduce manufacturing costs. It reduces several machining steps. They don't have to cut the checkering on the hammer spur. They don't have to mill holes for pins. They don't have to cut notches on jigs. They don't have to mill them into shape. They don't have to harden them after-the-fact. Nor do they have to hand-fit all those parts to make them work. All they have to do is have a monkey assemble them. If you think all that makes a better firearm, S&W will sell you all you want.

As for STI, I have yet to see or handle one. I'm sure they are as nice as reported, though I have absolutely no desire to own a fixed sight 5½" .45Colt single action. Ever. I know they are producing their Texican on EDM machines. An extremely precise machining method but very slow and unsuitable to mass production. Gunsmith David Clements produces hammers, triggers and barrels on similar machinery. The process is very well suited to small production runs. I have no firsthand knowledge of STI so I really can't comment any further. Although it does prove what finely built and precision revolvers can be built for not much more than a new S&W. If STI and USFA built double action revolvers, S&W would be dead to me.

About scratched hammers. The hammer well, or slot in the frame, is the same width from hammer pin to firing pin. So the only way to prevent the hammer from getting scratched as it travels into and out of the well is to either machine the slot wider at the top, which would be unsightly. Or to shim the hammer at the pin.