SEM images - cross section of MIM and bar stock 1911 thumb safeties.


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1858
February 15, 2011, 12:44 AM
Many manufacturers are using MIM parts in their pistols. I was curious to see if there are any obvious internal differences between MIM and bar stock parts so decided to cut up a pair of thumb safeties, one from Ed Brown and one from Kimber. I cut off the pin that passes through the frame and these images are looking at the cross section of those pins. I started at the outer edge and moved inwards towards the center. The Kimber MIM thumb safety is blued or painted but based on the EDXA (energy dispersive x-ray analysis) results, it could be stainless since it contains almost 11 wt% chromium and almost 3 wt% nickel. The Ed Brown thumb safety contains less than 1 wt% chromium and no nickel.

Ed Brown thumb safety - bar stock or cast

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/a_1.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/a_2.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/a_3.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/a_4.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/a_5.jpg



Kimber factory MIM thumb safety from a TEII

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/b_1.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/b_2.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/b_3.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/b_4.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/mim/images/b_5.jpg

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NG VI
February 15, 2011, 12:47 AM
Is that bad?

1858
February 15, 2011, 12:56 AM
Is that bad?

Not if it doesn't break. I was able to cut off the Kimber pin with a hacksaw but had to use a slow-speed diamond saw to cut off the Ed Brown pin. That Ed Brown thumb safety (the pin anyway) is hard!

Gtscotty
February 15, 2011, 06:26 AM
Honestly, you would expect the MIM part to have more voids and inclusions than a barstock counterpart. As long as the part has a decent heat treat and the inclusions don't reduce the fracture toughness to an unacceptable level, I don't see a problem.... This calls to mind the ever important engineering philosophy of "Good Enough"....

Hangingrock
February 15, 2011, 08:25 AM
This calls to mind the ever important engineering philosophy of "Good Enough"....
Yes and seldom understood by the multitudes.

FullEffect1911
February 15, 2011, 08:49 AM
What did you use to clean up the surface? Looks way to smooth for a hacksaw. Thank you for the pictures they are very interesting indeed.

gb6491
February 15, 2011, 09:22 AM
I was curious to see if there are any obvious internal differences between MIM and bar stock parts so decided to cut up a pair of thumb safeties, one from Ed Brown and one from Kimber. I cut off the pin that passes through the barrel link and frame and these images are looking at the cross section of those pins
I'm confused. Are these thumb safety pins or slide stops pins?
Either way, interesting and well done photos.
Regards,
Greg

Old Fuff
February 15, 2011, 10:35 AM
It is generally a given that MIM parts are a functional equivalent of those that are made from forgings or bar stock, but less expensive to make. If all these represent the best quality that can be produced using they’re respective technologies this might be true. An example might be MIM aircraft components that following manufacture go through extensive inspection procedures, often on a 100% basis. Gun parts on the other hand are made using MIM technology to make less expensive parts, and on a cost savings basis are not subject to any higher level of inspections.

In the case of a 1911 platform pistol, the slide stop pin is what keeps things together when the lower lug comes in contact with it as the slide and barrel go into battery. Remove the slide stop, and the whole upper assembly goes forward and off the frame. Thus the slide stop pin is subject to considerable battering, especially if the gun owner has unwisely installed an extra-strength recoil spring.

So while some may consider “good enough,” to be good enough, the Old Fuff would rather stake his neck on “the best,” and forget about cost saving and what may or may not be “good enough.” The posted photographs would seem to show that MIM parts are an “almost, but not quite” proposition when it comes to quality. Others of course may see things differently, and are welcome too do so.

Jolly Rogers
February 15, 2011, 11:19 AM
Very interesting photos. Thanks for the work involved.
Edited to add...Ed Brown does not claim that the safetys are barstock and I have seen photos of the back of the flange that show casting marks.
Here is the link to the manufacturers web page for safetys:
http://www.edbrown.com/thumbsafety.htm

Joe

ravot
February 15, 2011, 11:22 AM
awesome. thanks for the mini sacrifice. great to look at.

1KPerDay
February 15, 2011, 01:30 PM
cool pics. thanks for doing this.

1858
February 15, 2011, 01:35 PM
Honestly, you would expect the MIM part to have more voids and inclusions than a barstock counterpart. As long as the part has a decent heat treat and the inclusions don't reduce the fracture toughness to an unacceptable level, I don't see a problem.... This calls to mind the ever important engineering philosophy of "Good Enough"....

From what I've read, MIM parts can have up to 96-99% of the density of bar stock but I've never seen images of what the bulk of the part looks like ... now I have. I agree with your comment that there's an engineering practice of "good enough" which is driven by the need to make money. So how does a firearms manufacturer figure out what is good enough? You can bet that they have market studies indicating the typical round count of their products over their lifetime. So what may be "good enough" for one type of use or user, may not be "good enough" for another.


I'm confused. Are these thumb safety pins or slide stops pins?

My apologies and good catch. As I stated, they're thumb safety pins and I corrected my comment that the pin passes through the barrel link. It was late and I was rushing to get home. Sorry about that.


What did you use to clean up the surface? Looks way to smooth for a hacksaw.

I used a polishing wheel with a diamond slurry. I only spent a few minutes on polishing and would usually do a better job.


Ed Brown does not claim that the safetys are barstock and I have seen photos of the back of the flange that show casting marks.

True. Ed Brown uses either bar stock or "quality" castings. I changed the heading to reflect that. Thanks.

These images are merely showing the difference between two parts. One of the many things I like about the 1911 platform is that we don't have to settle for anything. We have a choice, many choices in fact, so we should all be able to "optimize" our own 1911s to suit our needs and expectations.

1858
February 15, 2011, 01:55 PM
In THIS (http://www.thehighroad.org/showthread.php?t=574359) thread, 9mmepiphany posted a link to Hilton Yam's website where he discusses MIM and selecting a 1911 for "duty use".

http://www.10-8performance.com/1911_Duty_Use.html

"The quality of the factory components will come into play when looking for a gun to use more or less out of the box. MIM (Metal Injection Molded) components, which have received an excess of attention in recent years, tend to vary in quality like anything else, but they can generally be expected to have a useable service life of 5,000 to 10,000 rounds. Some quality MIM components work exceedingly well, and I personally have witnessed a large number of guns with MIM small parts where service life has exceeded 30-40,000 rounds. Budget grade small parts that are "good enough" for a hobby level gun that may not get used very much are unacceptable for a service pistol where we should reasonably expect a service cycle of 3-10,000 rounds per year for 3-5 years. Be honest with your math in calculating your round count, as this article is meant to help you choose a reliable service weapon, not a fun time plinker for Sundays at the range."


I have a number of SIGs, both older and newer models. The newer models have three or four MIM parts but I'm not worried about those parts. I can order spare parts and will replace them if necessary.

Greg528iT
February 15, 2011, 02:19 PM
Thanks for the pictures. I was curious as to the cross sectional density myself.

I would like to introduce a concept that is more applicable to this.
Engineered by Accountant
As an Engineer (in aerospace, and know a few in aitomotive) a true Mechanical Engineer seldom picks, "good enough". We do select materials and processes that EXCEED the specifications.
That's when the cost accountants come in. They come in the slash at costs.
I often hear the term "German Engineering" when applied to cars. Really it's "German Cost Accounting" as in, the designs don't get slashed. Really are you expecting anyone to out Engineer and American Engineer. We put man on the moon. The difference between the stamped steel suspension member of an American car and a forged AL strut on a German car... all in cutting costs. Also why a Ford Taruas does not cost $75,000.

outerlimit
February 15, 2011, 02:50 PM
Here at Good Enough Firearms, we take pride in selling firearms for a premium price that are "good enough™".

Check out our upcoming Tactical Hillbilly Desert Road Warrior II 1911 clone at the next Shot Show. It will have groundbreaking features like forward slanted slide serrations, a sharp edged beavertail, only MIM small parts, skeletonized trigger, and they'll all be slapped together out of parts bins by highly skilled Filipino laborers.

Gidderdun!!

FullEffect1911
February 15, 2011, 03:22 PM
I'm not saying this is the case, but this could be a case of a good casting and a poor MIM part. I think it's safe to say that the Brown thumb safety is a good casting, as from what I've read in the past Ed Brown parts seem to be high end.

If it is at all possible I would love to see a Springfield MIM thumb safety chopped up and compared to the Kimber one (not sure if the springfield is actually mim or cast). Regardless I would like to see a direct comparison between what is considered a good MIM part and a poor one if it would be at all possible.

mroletta
February 15, 2011, 03:37 PM
"Better" is the worst enemy of "good enough", ha ha. One of the many important things I've learned in the field.

DammitBoy
February 15, 2011, 03:43 PM
http://www.blueloonfinearts.com/Merchant2/graphics/00000001/LestersAmmo_bear450.jpg

Jolly Rogers
February 15, 2011, 03:51 PM
True. Ed Brown uses either bar stock or "quality" castings. I changed the heading to reflect that. Thanks.


Manufacturers will trumpet any advantage they can in advertising. The fact that E.B. does not use the term "bar stock" or "forged" means they aren't.
There have been many instances of broken Ed Brown cast thumb safeties in the past that have been reported on various forums.

The fact that there is a distinct visible difference between the two parts is remarkable.
Joe

rellascout
February 15, 2011, 03:54 PM
Here at Kimber, we take pride in selling firearms for a premium price that are "good enough™".



Fixed that for you..... LOL :p :neener: :D

BlindJustice
February 15, 2011, 03:59 PM
INteresting thread - expecially in light of the fact my S&W 1911 thumb
safety broke at the pin last range session. ( and the plunger came off as well.) I looked at the Ed Brown thumb safety - just been waffling on
sending off the 1911.

Randall

Gtscotty
February 15, 2011, 05:04 PM
Here at Good Enough Firearms...etc

I've got some bad news for you.. every gun company is "Good enough Firearms"... every gun and indeed every product that passes through the drawing board is engineered to be good enough for what it needs to do, and is anticipated to do. What this means is that there is always a design goal, be it a certain factor of safety, a certain number of stress cycles, etc. there is nothing you use that has not been designed to fail at some point (in addition a decent engineer will have a good idea of where the part should fail, if they don't they don't really know their design's capabilities). This trade off is what constitutes the "Good Enough" in engineering, it is the heart of engineering.

You can bet that they have market studies indicating the typical round count of their products over their lifetime. So what may be "good enough" for one type of use or user, may not be "good enough" for another.

I totally agree, and that round count is what they should and do design to, because that is a reasonable design target for the vast majority of their users. Every gun company can't design all of their guns to shoot "fitty-eleven" rounds every day for 100 years, because then they wouldn't sell very many of their ultra-expensive wares. Instead they build guns that are good enough for almost every body... I think we are in agreement here.

I would like to introduce a concept that is more applicable to this.
Engineered by Accountant
As an Engineer (in aerospace, and know a few in aitomotive) a true Mechanical Engineer seldom picks, "good enough". We do select materials and processes that EXCEED the specifications.

I guess I'm not a true ME, because I tend to pick parts and materials that are Good enough to accomplish their intended purpose for the intended amount of time with a reasonable factor of safety. Oh well, guess I better go tell the boss... and all those lying professors.

In summation, I recommended that everyone cease buying Kimbers, I hear their safety is not made of mil-spec annealed Unicorn horn and thusly is prone to catastrophic failure long before the 30 bazillion round limit that most all pistols see in a lifetime.

The Lester's ammo pic is hilarious.

~$.02

1858
February 15, 2011, 06:35 PM
Manufacturers will trumpet any advantage they can in advertising. The fact that E.B. does not use the term "bar stock" or "forged" means they aren't.
There have been many instances of broken Ed Brown cast thumb safeties in the past that have been reported on various forums.

From Ed Brown's FAQ (http://www.edbrown.com/FAQ.htm#aau) ...

Do Ed Brown handguns have any MIM (metal injection molded) parts?

No, we use no MIM parts in Ed Brown firearms. While the current thinking is that MIM parts are "good enough" for firearm applications, this thinking doesn't fit with our philosophy at all. All Ed Brown parts are made from either forgings, bar stock steel, or quality investment castings.

I took a closer look at the Ed Brown thumb safety and I agree with you that it's cast. The rough region between the lever and the flat looks like it was left from the casting process. Also, I notice on the Ed Brown thumb safety packaging there's a warning about blending the safety flush with the frame. I wonder if any of the "many" breakages that you refer to are as a result of cutting too deeply into the pin area.

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/ed_brown/photos/ed_brown_thumb_safety_2.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/ed_brown/photos/ed_brown_thumb_safety.jpg



Instead they build guns that are good enough for almost every body... I think we are in agreement here.

Yes, I agree with that.



If it is at all possible I would love to see a Springfield MIM thumb safety chopped up and compared to the Kimber one (not sure if the springfield is actually mim or cast). Regardless I would like to see a direct comparison between what is considered a good MIM part and a poor one if it would be at all possible.

PM me and I can give you my address if you want to send me a Springfield thumb safety for comparison. I think I'll chop up my spare Kimber MIM slide stop since I don't plan on using it. As Old Fuff stated, that's an important part.

Walkalong
February 15, 2011, 08:56 PM
Cool pics.

I put a Wilson thumb safety and slide stop on my Kimber (http://www.thehighroad.org/attachment.php?attachmentid=113515&d=1263749343). I feel better about them than the stock parts. I modded the lever on the thumb safety and bead blasted both items to match the gun. I replaced the hammer and sear pins with Ed Brown pins.

DammitBoy
February 15, 2011, 09:12 PM
In summation, I recommended that everyone cease buying Kimbers, I hear their safety is not made of mil-spec annealed Unicorn horn and thusly is prone to catastrophic failure long before the 30 bazillion round limit that most all pistols see in a lifetime.


Hah! Good Fun!

I sure wish I could get some annealed unicorn horn for some 1911 grips I wanna make...

FullEffect1911
February 16, 2011, 10:30 AM
I sure wish I could get some annealed unicorn horn for some 1911 grips I wanna make...

Oh dear, I don't think PETA would like that at all. :D

send me a Springfield thumb safety for comparison.

If I can find my old one around I will.

Big_E
February 16, 2011, 10:36 AM
Enough about the metallurgy, what piece of equipment did you use to take those photos?

**I'm such a geek.

1858
February 16, 2011, 10:45 PM
So I cut up the MIM Kimber slide stop that came with my TEII. I cut off the pin that passes through the barrel link. My first impression was that this was a very dense and uniform part, then I started to look around, particularly near the outer edge and found some regions that didn't look quite so homogeneous. This indicates to me that it might be a challenge to make a part that is consistent throughout. Any part, regardless of how it's made, can fail, so take all of this for what it is.

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_slide_stop_01.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_slide_stop_02.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_slide_stop_03.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_slide_stop_04.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_slide_stop_05.jpg

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_slide_stop_06.jpg

The dark spherical "particles" are silicon, or at least, are showing high silicon levels. I don't know if these are artifacts from the injection or heat treating processes but they're not present in the cast part from Ed Brown. I'm more familiar with the heat treatment of aluminum alloys where spherical magnesium silicide precipitates during the heat treatment process. In aluminum, these precipitates add to the strength, but I don't know if the same is true for MIM parts.

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimbe_silicon_peak.jpg
http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_silicon_spectra.jpg


Here's some info showing the elements in the Kimber thumb safety which has significantly more chromium and nickel compared to the slide stop.

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_safety.jpg
http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_safety_spectra.jpg


Here's some info showing the elements in the Kimber slide stop.

http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_slide_stop.jpg
http://128.171.62.162/hawthorn-engineering/thr/pistols/1911/kimber/photos/kimber_slide_%20stop_spectra.jpg

1858
February 16, 2011, 10:56 PM
Enough about the metallurgy, what piece of equipment did you use to take those photos?

They're images rather than photos (there's a difference) and I use an Hitachi S-3400N scanning electron microscope (SEM) with an Oxford Instruments Energy Dispersive X-ray Analysis (EDXA) detector to obtain the elemental data.

bnz43
February 17, 2011, 02:42 PM
How were the parts cut apart? The cut is so clean it almost looks like an EDM process. Really cool analysis of the MIM parts versus the forged parts.

Toforo
February 17, 2011, 02:50 PM
Ahh - those pics posted by the OP reminded me that I need to pick up bologna from the Deli in the morning and have it sliced thick -

Thanks!

:p

Big_E
February 17, 2011, 03:00 PM
They're images rather than photos (there's a difference) and I use an Hitachi S-3400N scanning electron microscope (SEM) with an Oxford Instruments Energy Dispersive X-ray Analysis (EDXA) detector to obtain the elemental data.

Ah yes, I realize my mistake. I'm a biology student and have grown up around microscopes, I should have known better :(. 1858, would you mind telling me what you do for a living? Or how you have access to such equipment.

Thank you for taking these images, it can affect the argument of cast vs. MIM. While I am sure that some people with MIM parts haven't had a failure yet, if I am going to carry my 1911 (or any pistol) I sure do not want to risk the event of a part breaking. Plus, is there any regulation as to how many impurities are involved in the MIM process?

1858
February 17, 2011, 03:01 PM
How were the parts cut apart? The cut is so clean it almost looks like an EDM process. Really cool analysis of the MIM parts versus the forged parts.

Typically cut with a low-speed diamond impregnated blade and polished using a slurry containing very small diamond particles. We have 30, 9, 3, 1, 0.5 and 0.05 micron solutions for polishing. I don't know if this interests you or not, but in order for scratches in metal to remain undetected using most imaging processes, the width and depth of the scratch needs to be less than about 0.3 microns since the shortest wavelength of visible light is 380nm. In other words, if the width/depth of the scratch is less than the shortest wavelength of visible light, no light can enter the scratch and be diffracted irregularly. It's variances in diffraction that reveal scratches.

1858
February 17, 2011, 03:21 PM
1858, would you mind telling me what you do for a living? Or how you have access to such equipment.

I'm a mechanical engineer working on projects funded by a number of branches of the armed forces including the Air Force, Army, Marine Corps and Navy. We're involved in material selection and testing, short and long-term testing of components and systems, coatings, corrosion control etc.


While I am sure that some people with MIM parts haven't had a failure yet, if I am going to carry my 1911 (or any pistol) I sure do not want to risk the event of a part breaking.

This is my approach too. I only have two 1911s, one came with no MIM parts (Ed Brown) and other came with a bunch (Kimber TEII) but I replaced most of the MIM parts. I shoot the Kimber a lot i.e. a rate of about 10,000 rounds per year and many of those rounds are in matches. I might shoot more than that this year if I can take a two or three-day course from Bruce Gray which is my plan.

My feelings at this point are that MIM serves a purpose for many owners and for manufacturers. MIM helps to reduce cost, provides sufficient quality and longevity for many and makes the swapping of parts easier (less fitting) which is good for the end user. However, some parts are more critical than others depending on the loading and fatigue along with the number of defects in the part. I still feel that I have less chance of a catastrophic failure in a match or class if I'm using high quality bar stock, forged or cast parts compared to MIM. Peace of mind is important, even if it's based on a false premise.

Plus, is there any regulation as to how many impurities are involved in the MIM process?

This would be negotiated between the manufacturer of the MIM parts and the firearms manufacturer assuming they're not one and the same. For example, I'm sure that Kimber cuts up MIM parts and inspects them to determine if the chemistry and heat treatment are acceptable. They'd also inspect the parts to ensure that they're dimensionally accurate. The problem is that you can't cut up every part so it's a statistical process where you're confident of X number of parts being "good enough".

Zerodefect
February 17, 2011, 08:57 PM
My EB big paddle thumb safety is Cast. LB is cast. STI cast. Most Wilsons are cast.

The only billet and forged thumb safeties I know of are Wilsons top shelf safety (thier lower models are cast), and the Dan Wesson thumb safety on the 2010+ Valors and Vbobs.

918v
February 18, 2011, 03:02 AM
This calls to mind the ever important engineering philosophy of "Good Enough"....

nothing to be proud of

918v
February 18, 2011, 03:05 AM
The only billet and forged thumb safeties I know of are Wilsons top shelf safety (thier lower models are cast), and the Dan Wesson thumb safety on the 2010+ Valors and Vbobs.

SVI makes a billet thumb safety as well.

Hangingrock
February 18, 2011, 07:57 AM
There is in every design cost and effect. How many $2500-$3500 1911 series pistols are sold in comparison to the polymer frame striker fire pistols that dominate the market place? Yes-yes I know apples oranges comparison but which is more cost effective and or durable.

It would be enlightening to conduct a 50,000 (just as an example) round endurance test of a high end 1911 and a Glock/S&W polymer framed striker fired pistol and see which one gives up the ghost first.

There are certain designs which one could say are over engineered for the application and then there are good enough designs for the application. None the less cost is an issue like it or not.

jeepmor
February 18, 2011, 08:01 AM
Nice comparison. The MIM parts definitely have a higher defect density. I used to do SEM work for 7 years in semiconductors. A+ on imaging and EDX data collection.

I think you've illustrated the MIM, Non-MIM part differences quite well. All this "good enough" talk is fine and the engineers overseeing the mfg process will be putting the metric on the "good enough" (acceptable) defect density levels. But the data clearly illustrates to me that a machined part will be more reliable than a MIM'd part based upon empirically observed defect density level comparison. There's simply more opportunity for failure with higher defect levels in the MIM parts in this example.

Jolly Rogers
February 18, 2011, 08:43 AM
1858....nice toys! I would like to have a barstock part and a forged part cut and imaged also. This could be the definitive thread about quality in MIM, cast,barstock and forged parts. The arguments would all cite this thread. :cool: There was a nice thread over at the 1911 forum in the gunsmithing subforum about slide stops and thumb safty quality but it is not accessable at this time. Weeks down for maintenance... I hope it comes back as I would reference this data.
Many thanks for your effort. If I had any parts to add to the database I would send them..alas...:(
Joe

918v
February 18, 2011, 12:06 PM
Do a search here for cast vs forged. 1858 compared cylinders from a Ruger to a S&W last April I think.

1858
February 18, 2011, 01:55 PM
Do a search here for cast vs forged. 1858 compared cylinders from a Ruger to a S&W last April I think.

Take that thread for what it was, interesting and mysterious images of S&W and Ruger cylinders and nothing more. Many manufacturers use proprietary materials and techniques and guard them closely and Ruger is no exception. I don't think any company wants enthusiasts like me cutting up their parts and posting results on the internet. My take is that if you have nothing to hide then you'll bend over backwards to help those individuals spread "the good word". However, I was contacted by Ruger's Associate General Counsel and I have little doubt that they were flexing their muscles. I took the hint. If you notice, I'm simply providing images and EDXA data without offering any significant conclusions. The last thing I need is Kimber's legal department sending me an email.

Jolly Rogers
February 18, 2011, 04:20 PM
The photos are prima facie evidence of the comparative quality of the parts, and need no comment.
Joe

Pizzagunner
February 18, 2011, 05:03 PM
My personal take on MIM is this: There are pistols that are designed from the clean sheet that take into account that certain of its parts will be MIM from the get go. The S&W M&P series would be a prime example of such a design. M&Ps have put up impressive round counts without its MIM sear failing catastrophically. The wear characteristics, impact resistance, etc., were all taken into account in the CAD/CAM process and confirmed through developmental testing and field use.

OTOH, MIM is also being adapted to parts for designs that were made before MIM was a process, (1911s, SIG P22x, S&W revolvers, etc.). These are the applications of the technology that I do not fully trust as what has actually happened is a material strength downgrading that was not accounted for in the original design engineering, developmental prototyping, nor years to decades of field use.

Coming full circle to the M&P. Suppose that a decade from now S&W decides that a hard polymer sear will wear and perform "well enough" to replace the MIM sear. I'd find that claim suspect and more likely a child of the accounting and legal departments than of the R&D department, absent any widely publicized general breakthrough technologically in wear resistant polymers.

MIM is a fine technology when properly used in a dedicated design application. Using it to replace bar stock parts or quality IC parts on vintage designs is a cost cutting strategy that is not also in the best interests of the end user on any other front save price.

tekarra
February 18, 2011, 08:04 PM
1858,
Any chance that you can polish and etch those parts and take some photos on a metallograph? It would be interesting to see the grain structure.

918v
February 18, 2011, 11:32 PM
However, I was contacted by Ruger's Associate General Counsel and I have little doubt that they were flexing their muscles.

I will never buy a Ruger again. Your statement just sealed the deal.

Pizzagunner
February 19, 2011, 12:53 AM
His statement is a very paranoid reading of the exchanges with Ruger he posted in that thread. I don't even like Ruger, they were just saying that the information sought was proprietary. Then another source at Ruger told him that the cylinders in question were milled from different formulations of bar stock, which just happens to jibe with what two people who've actually toured Ruger's NH facility said in a book and live within that thread.

You can boycott Ruger for all I care, but don't base it on 1858's reading of emails he published in a thread, emails which would threaten no rational person, and which didn't even chill him enough to dissuade him from pressing Ruger for "non-proprietary" ways of answering his queries, which they did.

If they were "flexing their muscle" he's only seen it in retrospect.

Ridgerunner665
February 19, 2011, 01:10 AM
It would be enlightening to conduct a 50,000 (just as an example) round endurance test of a high end 1911 and a Glock/S&W polymer framed striker fired pistol and see which one gives up the ghost first.

I like Glocks...but if you shot the pistols until the frame got hot enough to melt, the 1911 would win. (Glock frames will start to droop after a while...)

918v
February 19, 2011, 02:34 AM
His statement is a very paranoid reading of the exchanges with Ruger he posted in that thread. I don't even like Ruger, they were just saying that the information sought was proprietary. Then another source at Ruger told him that the cylinders in question were milled from different formulations of bar stock, which just happens to jibe with what two people who've actually toured Ruger's NH facility said in a book and live within that thread.

You can boycott Ruger for all I care, but don't base it on 1858's reading of emails he published in a thread, emails which would threaten no rational person, and which didn't even chill him enough to dissuade him from pressing Ruger for "non-proprietary" ways of answering his queries, which they did.

If they were "flexing their muscle" he's only seen it in retrospect.


Did S&W's general counsel contact him?

The fact that a major gunmaker's general counsel intervenes in a pictorial show and tell says alot.

1858
February 19, 2011, 02:15 PM
His statement is a very paranoid reading of the exchanges with Ruger he posted in that thread. I don't even like Ruger, they were just saying that the information sought was proprietary. Then another source at Ruger told him that the cylinders in question were milled from different formulations of bar stock, which just happens to jibe with what two people who've actually toured Ruger's NH facility said in a book and live within that thread.

Not only are your comments inaccurate, they're also naive. Only one individual contacted me from Ruger and that was their Associate General Counsel in my response to an email that I sent to customer service. Is this normal operating procedure to you? A question directed to customer service gets answered by the company's legal counsel. This isn't some rinky dink small business, this is a publicly traded company on the NYSE. I found it odd at the time, and still do, but that thread had run its course so I backed away graciously. I knew that no further progress was possible without cutting up those cylinders and having experts in the field of casting look at them. Passivation processes won't affect the internal structure but I wasn't prepared to sacrifice my cylinders for this forum. That's too much cost for something that really isn't that important. I love Ruger revolvers and currently have six of them with plans for more. Ultimately, does it matter how Ruger makes their product if they work, which they do?

1858
February 19, 2011, 02:25 PM
Any chance that you can polish and etch those parts and take some photos on a metallograph? It would be interesting to see the grain structure.

I'm going to cut up more Kimber and bar stock parts first, but I can try etching some parts after that. I have access to all kinds of chemicals so should be able to obtain or make a suitable etchent.

Tinman357
February 19, 2011, 02:42 PM
For my personal comfort I settled on ONLY high end Wilson parts for my personal 1911. Yep, MIM is good enough, Yep, cast is good enough. I prefer forged bar stock for reasons of my own. Yep, it breaks as well. :scrutiny: heard about it, never seen it. Just my personal choice.

Great images. Thank you.

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