MIM??

[481]

I would wager that 1911 fans complain about MIM more for two reasons:

Their guns are extremely expensive to begin with, and MIM is seen as a process used to save money (which implies cutting corners, to some).

Also, the gun is all metal. You don't hear Glock fans complaining about MIM because MIM doesn't matter when the bottom half of your gun is plastic anyway.

So is MIM.

M(etal) I(njection) M(olding) is actually a fabrication process and not a material in and of itself.

Many different metals can be used to produce MIM components (including stainless steel) and I'd contend that it is a viable process and no less stronger than any cast or forged part.

Some companies are even making guns with MIM barrels (See page 38 of the February 2010 issue of Combat Handguns) like the Cobra Shadow .38 Special revolver. This is impressive to say the least and speaks volumes as to the strength and viability of the process. Their MIM barrel is even rated for +P ammo! That's 20,000 psi.

MIM is kinda neat IMO, for its almost ceramic-like production technique (parts are injection molded and then fired like pottery in a kiln) and its resultant impressive strength.

Initially, I distrusted and disliked the process, but as I've investigated it and learned about its attributes, it ain't so bad afterall. Got a new respect for MIM after beating the snot out of a MIM part with a ballpeen hammer (see post #16 page 1 of this thread) and was pleasantly surprised when it wore me out and "went the distance" against the hammer.

 

[John Wayne]

I know what "MIM" stands for. My point was that buyers of 1911s like their expensive guns to look good--and while MIM may be just as tough as machined steel, it is not an attractive looking material.

Since Glocks use polymer frames and are rather ugly to begin with, no one cares about MIM in them.

 

[fastbolt]

MIM parts don't worry me as long as they're used for applications compatible with their properties and the inherent strength of a properly produced MIM part.

Lesser quality MIM parts would concern me.

FWIW, poorly made cast, stamped and forged parts concern me. I've had more problems with those than with good quality MIM parts.

 

[Jim K]

It is interesting that Ruger is being held up as a quality company because they use castings. At one time, any cast (or stamped) part in a gun made it complete junk, on a par with cap pistols. Only forged and machined parts were considered good enough for real, true-blue American guns. The German P.38 was widely denounced by Americans as being "stamped out" and "cheap junk" because it used a few stamped parts. Every new manufacturing process will be condemned, reluctantly accepted, then praised as the good old way as soon as something else comes along. MIM is no different.

Here is a case in point. After S&W began use of the rebound slide, the trigger had a tiny coil spring, a hand lever, a trigger lever, and two tiny pins. The trigger had four small holes drilled in it for the pins and the hand. The MIM trigger still has the holes for the hand; the others are gone, along with the coil spring, the hand lever and the pins. The trigger lever interlocks with the trigger, eliminating a hole and a pin. The hand spring is a wire spring, eliminating the coil spring, the hand lever, and a pin. Assembly time must be a tenth of the time the old trigger took.

So, why is the price still high? Wrong question. The right question is how much higher would the price be without MIM and other manufacturing short cuts?

A lot of folks lament the passing of precision machining and hand fitting. But they would lament even louder if gun makers returned to those practices and charged accordingly. Can they turn out guns "like the old days"? Sure. Want to buy a 642 at only $2500?

Jim

P.S. I once read an article (vintage 1900) on the use of steel in guns. The writer pointed out all the problems of steel and said that wrought iron and bronze were far superior. Further, he pointed out, use of steel in shotgun barrels meant the end of beautiful Damascus craftsmanship. He was right. Anyone want to go back?

Jim

 

[huntsman]

Only forged and machined parts were considered good enough for real, true-blue American guns.

Ahh the good old days when men were men and guns were steel

 

[481]

It is interesting that Ruger is being held up as a quality company because they use castings. At one time, any cast (or stamped) part in a gun made it complete junk, on a par with cap pistols. Only forged and machined parts were considered good enough for real, true-blue American guns. The German P.38 was widely denounced by Americans as being "stamped out" and "cheap junk" because it used a few stamped parts. Every new manufacturing process will be condemned, reluctantly accepted, then praised as the good old way as soon as something else comes along. MIM is no different.

Jim,

I could not agree more with this, especially your last sentence. It is kind of what I was goin' for in my prior post and I wish that I had been as eloquent.

Good job.

 

[Singlestack Wonder]

All of the aluminum wheels made for cars are now injection molded.....

 

[Runningman]

I actually don't have a problem with MIM parts...... IF they are done correctly. The automotive industry has been using MIM parts for many years. GM has made their engine connecting rods out of MIM parts since the 90s. Many of the automotive factory aluminum wheels are made from MIM process and they are very tough.

However for whatever reason more than a few gun manufactures seem to have a problem getting good consistent high quality parts from the MIM processes. Got to wonder if they are on a learning curve here.

With the exception of Ruger, who as far as I know uses investment cast parts for their guns (makes sense), I'd love to hear about a manufacturer who does NOT use at least one MIM part these days. Seems to me that most auto loaders these days are at least using MIM in the extractor, hammer, trigger, sears, or all of these and more parts.

If anyone knows of a gun manufacture who is not using any MIM parts at all in their products, please post them, I for one would like to know.

So far I have not seen a MIM part used on any of the CZs I own. CZ does use a investment casting for their frame on the CZ 75/85 and CZ 97.

 

[DBR]

One of the reasons gun manufacturers have had trouble with their MIM part endeavors is they low ball the tooling and manufacturing sources. It is my understanding that is what initially happened with Kimber. To Kimber's credit they rapidly fixed the problem.

A homogeneous forged or even a cast part is more tolerant of process errors than a MIM part which is composed of discrete particles of the base metal and a resin which must be fused together to make a coherent part.

Properly made MIM parts can be superior to cast or forged parts at a lower cost. Part of the "ugly look" of MIM parts is like most molded parts the process doesn't like thick sections.

 

[Confederate]

Can they turn out guns "like the old days"? Sure. Want to buy a 642 at only $2500?

Hmmmm...so older classic models should sell for more than modern "cut corner" versions? There are older guns out there which have never been fired, yet most people won't pay the extra $$$ for them, and "blue book" values don't reflect the superior crafsmanship and materials. (Bill Ruger said they never made a dime off their Security-Sixes, yet the printed values of the gun are still cheaper than they probably should be -- though that's changing.)

I would pay more than going price for an older 686, with chromed hammers and triggers and one-piece barrel and front sight just because I like the crafsmanship. (I'd still like to find a "new" S&W 66 with recessed barrel and stamped sideplate and a 4-inch barrel.)