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Post by AxeHandle on May 7, 2013 10:14:41 GMT -5
These MIM parts we see in current S&W revolvers... Should we expect them to maintain their structural integrity when we significantly modify their shape? Specifically talking about hammers and completely removing the spur.
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Post by bradshaw on May 7, 2013 10:30:41 GMT -5
You raise a valid vein of inquiry, Axe. One I won't attempt to answer. I know that Rugers senior and junior looked into metal injection molding, found the technology valid with limitations, and decided it DID NOT FIT what they were making.
Ruger also did not use case carburized or surface hardened parts. Unlike the case hardened triggers and hammers of S&W and Peacemaker frames of Colt, Ruger only "through hardens."
My S&Ws are old school and someone is going to have to live and shoot a long time to demonstrate a MIM hammer and trigger is anywhere near as good----let alone better.
And, yes, MIM parts can break. David Bradshaw
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Post by hammerdown77 on May 7, 2013 10:36:14 GMT -5
leftysrh lopped the hammer spurs off of his and is running them in competition. They are MIM parts I believe.
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Post by jiminyt on May 7, 2013 10:36:34 GMT -5
MIM parts should not be any different than cast or machined small parts, if they are made correctly. However, like any other part you are going to modify in a gun you should be aware of any subsequent conditioning treatments that metal has had, ie. heat treating, plating, etc.
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Post by AxeHandle on May 7, 2013 11:39:02 GMT -5
Thanks guys. Went to the S&W forum and found an old thread that pretty much said the same thing...
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Post by bradshaw on May 7, 2013 16:03:53 GMT -5
Axe.... please re-read my above note on the William Rugers', father & son, take on MIM parts. Both decided against MIM parts on their guns. They noted that powdered metal works well for some parts, but lack the high tensile quality required for others.
Take the Ruger single action, for example. The pawl and transfer bar are two of the many investment (lost wax) cast parts. No idea what sort of stresses are imposed on the pawl and transfer bar, but the loads are serious, especially under fast draw and high volume fire. The Ruger investment cast parts leave little or nothing to be desired. David Bradshaw
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Post by AxeHandle on May 7, 2013 16:48:35 GMT -5
Cautions noted David.... I rather have something other than MIM parts myself. FWIW I cut into the MIM hammer today. Surface seemed pretty hard. Inside seem pretty homogenous.. Only time will tell.
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Post by boxhead on May 8, 2013 5:54:41 GMT -5
I have a whole lotta faith in S&W and their materials capability. Do data but no worries either. If it breaks, buy another just as we do when Ruger, Colt, Winchester and Remington parts break, forged, cast or whatever.
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Post by hammerdown77 on May 8, 2013 11:26:36 GMT -5
Yep, S&W have been using MIM for their internals for a long time now, and if there had been a rash of failures we'd have heard about it. They, unlike Kimber's initial foray into MIM parts, seem to have figured out the correct way to apply the technology.
Ruger is using MIM for some of their double action triggers (and maybe hammers) now too, aren't they?
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Post by cas on May 18, 2013 10:42:57 GMT -5
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Post by bigbores on May 18, 2013 13:19:42 GMT -5
I agree completely with cas. Some of the most stressed factory automotive engine parts are made using MIM, I wouldn't trust them in a race car but GM uses MIM made connecting rods.
Here's some info on a turbo manufacter using MIM parts.
Variable geometry turbochargers (VGT’s) are designed to allow the aspect ratio of the system to adjust to optimum levels depending on engine speeds. A key component in this system is a ring of aerodynamically-shaped, moveable, vanes in the housing at the turbine inlet.
Complex geometry combined with a high temperature corrosive environment are ideally matched to the shape and materials capabilities of the Metal Injection Molding (MIM) process.
Application Details
Turbocharged or Supercharged Petrol and Diesel engines with VGT systems Vanes, levers, and adjustment rings Automotive, marine, and industrial engines
Advantages
Nearest to shape capabilities - only minor machining required Unique high temperature corrosion and wear resistant materials Proven manufacturing capability
Material: Steel
Process: Metal Injection Molding 12345
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foxtrapper
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Post by foxtrapper on Jun 13, 2013 8:30:13 GMT -5
Outdoor channels shooting gallery tv show did a segment at the Taurus plant in Brazil. They showed the making of MIM parts along with comment. Shows host said the MIM are gtg. Maybe you can download the show off their website.
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Post by jiminyt on Jun 13, 2013 13:16:11 GMT -5
Hard to believe those hammers have enough mass to discharge the primers.
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Post by bradshaw on Jun 14, 2013 12:19:07 GMT -5
Obviously, powdered metal technology has evolved greatly in recent years. I expect these parts are much better than early MIM hammers and triggers. Railroad "ribbon rail" is welded in place with powdered steel and flammables poured into a funnel, ignited and covered. A ceramic mold around the track ends, which have an inch or so gap, contains the molten ingredients as they fuse the tracks. As most pounding of rail occurs at track joints, the ribbon rail keeps the track straighter and saves maintenance. It is not without challenge, however. Some years ago a friend traveling across Canada in winter sat for days in 20 and 30 below ZERO fahrenheit as track was repaired. The cold shrank the unjointed track over miles and the tension popped the steel.
Intrigued by the "race refinement" of DA lockwork to lighten trigger pull and hasten hammer fall for double action shooting. This specialization for competitive shooting makes me wonder whether my Cummins Dodge with solid axles front and rear is an antique, despite its extreme reliability under adversity, and whether I might better be served by titanium independent suspension. Fortunately, I cannot afford to lose sleep over it. More particularly, I wonder how the supper lightweight MIM lockwork holds up under full house magnums. Is there potential for primer blanking under the light hammer? Or 25 below ZERO ignition questions?
One last observation: there is a huge gap behind the second MIM hammer illustrated. What happens when this fills with chainsaw shavings, dust, and snow?
These questions have been answered in full by old school revolvers through decades of durable performance under the most arduous conditions. Therefore, the questions remain valid. David Bradshaw
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Post by packingheat on Jun 15, 2013 18:13:44 GMT -5
I just broke the bottom pin off of the hand of my Smith and Wesson Governor in about a hundred rounds. I am very disappointed in the MIM parts.
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