this is what stands out to me in the orginal OP thread about smith's statement....here is part of it and i will "bold" selected parts to mark concern....
Let's shift gears for a moment and talk about the MIM process. It is unclear to me as to the reason for many of the negative feelings on the forum concerning MIM. Typically when people complain and aren't specific in the reason why, the problem is often created by a departure from the "Traditional". Perhaps that is indeed what is bothering some people when they view MIM.
The term MIM stands for Metal Injection Molding. It holds some similarities to Plastic Injection Molding and many differences as well. To start we would take a finally divided metal powder. This could be stainless or carbon steel. Today even titanium is being used in some MIM fabrications. We would mix the metal powder and a thermoplastic binder (generally a wax) forming slurry of sorts when heated and inject this mix into a precision mold and finally form what is known as a “green part". This part is roughly 30% larger than the finished part it will become at the end of the process. Interestingly enough the green part at this stage can be snapped in two with simple finger pressure. The green parts are then placed in a sintering furnace filled with dry hydrogen gas and the temperature is brought almost to the melting point of the metal being used. Over time the wax in the green part is evaporated, the metal fuses and the part shrinks 30% to it's final correct dimensions. At this stage of the process the MIM part has developed 98 to 99%of the density of the older wrought materials and a metallurgy that is almost identical. Dimensionally it is finished and no machining is required. However the job is not yet done and the MIM parts are brought to our heat treat facility for hardening and in the case of hammers and triggers, case hardening. Depending on the particular metal alloy that was used at the start of the process we apply a heat treat process that is the same as would be used if the material were the older wrought style. Final hardness, case thickness and core hardness are for the most part identical to parts manufactured the older way.
i am not a rocket scientist, i am not an engineer............the items in "bold" tend to not create warm and fuzzy feelings.
these concerns are about MY ignorance on the subject. powdered metal and thermoplastic flies right over my head and does not particulary sound stout or "right".........sounds down right unsanitary and unhealthy if you know what i mean.....
sintering.....mercy, there was a lot of bad talk years back about sintered gun parts.....
but again, smith is trying to explain this process to this ignorrant person and not doing a very good job of it..........all of the positives in the article have been canceled by word association with the perceived negatives.
then, there is the wonderful world of the internet. rumors abound, and people feel compeled to take sides. Some examples start getting thrown out back and forth pro and con and soon enough the waters get muddy.
Talk of gunsmiths who claim you can not "work" an MIM gun, polish/mill the surface too deeply and you are into soft metal......and claims to the contrary.
Taurus uses MIM?.......i could not care less
Ruger is now using MIM?......now that gets my attention
MIM is apparently here to stay. The real problem today in my opinion is not the parts process, but the quality control......be it parts or finish or screwing the barrel on straight.
and just sheer speculation here, but this revolver guy was a hold out for a long time against autos in general and plastic autos in particular........revolvers were trusted to be reliable, stout, and made of real steel and not plastic or powdered metal...............but they did eventually drag me kicking and screaming into the current century.....
my next revolver will probably be an airweight smith 638 with a hillary hole.........it will be less expensive than a pre-mim "hole-less" model on the used market. All this debate has done is drive the prices of used smiths up to the point that i might as well just get a new one.