I see all the time where people talk about MIM tech and the pros and cons. I’m not an engineer nor do I know anything about metallurgy. This really gave me a new respect for MIM parts and their place in firearms.
The link didn’t work.
Not sure why it would evoke respect, but here’s the link:
http://www.phillipsmedisize.com/defense/capabilities/metal-injection-molding-mim
“MIM Tough”…first time I EVER saw MIM touted as preferable…talk about spin.
I fixed the link. The reason I was impressed were the parts that were MIMed. Hammer, Unlocking Block, and extractor. The link is to a full case study its quite interesting. I know most polymer handguns these day incorporate MIMed parts, but which parts are MIMed is often unknown. This case study puts it out in the open. I found it interesting that a company such as FN would put so much on the line with MIM technology.
Here’s the deal. MIM is OK if you have an engineer that knows what the hell he is doing. Knows its limits and its weaknesses. Parts Engineered for MIM and made out of MIM from the get go are no better or worse than parts Engineered and Made out of any other type of material.
The big problems come and lie in when someone takes a part of whatever the type of material is and then takes the same engineering dimensions for that material and says ok lets make this out of MIM. If you don’t change some dimensions and specs for the Differences of MIM then the part WILL fail almost guaranteed. HK uses MIM FN uses MIM Smith uses MIM BUT they started the engineering phase with hey we can makes this out of MIM and design it for MIM from the get go. You get problems when idiots make decisions to make standard cast or tool steel parts out of MIM. “Cough Glock extractors Colt AR15 Mag release.”
It’s not like MIM is new technology. I think rotorblade makes an excellent point in that if MIM is part of an engineered solution, not just a cost saving measure to replace a forged/machined/non-MIM part without any additional engineering consideration, the results can potentially be less than desirable. MIM has successfully been used in plenty of other industries and has some definite production and cost advantages, but has developed a rather negative stigma in the gun world, somewhat due to preconceived notions of what a part “should” be made of and somewhat due to poor implementation of MIM parts and subsequent issues due to issues previously mentioned. I don’t think that article should really evoke more “respect” or why it would be perceived that FN is putting anything on the line using MIM. If they properly engineered the product with MIM parts and have vetted the parts through testing, then what they are made out of doesn’t matter.
No engineer here, but I’ve yet to see someone going through a Colt 1911, S&W Revolver, or other gun trying to replace forged parts with more MIM. Typically the other way around. YMMV.
I agree. I have been down the same road of replacing MIM parts in several of my guns. In almost every part I replaced, the surface finish and quality of the part was superior to the MIM part it replaced. In some cases it yielded a real improvement (sears, hammer, etc.) or maybe it was just peace of mind (extractors). However, I personally have no data to show whether the MIM part was actually weaker or less reliable than the machined part. It just seems that in the case of gun manufacturers that it is only a cost saving measure, not because the MIM part is superior.
As someone who works with metal, I often opt to upgrade to tool steel parts because I at least know the composition of the part that way. For example, I don’t know what the MIM part comes from in a regular thumb safety, but if I install a 10-8 one when replacing a GI style one, I know its been “CNC machined from heat treated bar stock”. The company I work if very careful how they pend their money, and there’s good reason why they pay a hefty premium for some steels.