[Just Jim]

What year did each company start using MIM parts? Just so collectors know.

jj

[JohnBT]

I have no idea, but it's been used for quite some time. I think gun makers were relative latecomers to the party.

"AFT Products. Metal injection molding (MIM) is a technology
that enables the production of small, complex, net shape metal
parts at a significant cost savings over machining, investment
casting or other net shape and near net shape processes. It is a
hybrid manufacturing process which combines elements from various
other fabrication methods, including powder metal processing,
investment casting and plastic injection molding. MIM provides a
technological advantage over other fabrication methods in its
ability to produce small complex parts with thin wall sections,
sharp corners, edges and other interior details that cannot be
produced economically by other processes. AFT's MIM parts have
been used in electronic, medical, firearms, military ordnance,
automotive, fiber optic, aerospace, and other industrial
products."

[4v50 Gary]

I learned in Armorer's School (1985) that Colt was among the first to start using MIM parts when they came out with the newer Colt Trooper (non-Python action). It was called sintered metal back then and like any modern mim part, if the surface hardening wears out, it fails.

[Wild Deuce]

Is there any firearm manufacturer not using MIM parts?

[Cosmoline]

Ruger uses their own casting process for most of their firearm components.

[Jim K]

Sintered metal is not the same as MIM, though there are similarities in the process. MIM has been around a while, but got a bad rap in the gun industry when companies farmed out MIM manufacture to non-gun companies and got poor quality work. Properly done, and where appropriate, MIM is perfectly fine and allows parts not only to be made with no waste, but to be made in ways that would be difficult or impossible to make by any other method.

Like other new manufacturing methods, MIM needs to be used appropriately. For example, we generally accept polymer frames and recognize that they are not the "cheap plastic" they were once described as, but no one would use polymer to make a barrel or a hammer.

Jim

[45auto]

I believe Remington was an early user of MIM also.

[Sunray]

"...Ruger uses their own casting process..." Ruger has always used investment cast parts. Making investment castings is one of their side businesses.

[Jim K]

Here is an article that gives the surprising origin of MIM as well as explaining the difference between MIM and sintered metal.

http://www.alberox.com/articles/mim.htm

Jim

[Just Jim]

So it looks by the article that MIM started in 1989. So guns made before this date should be MIM free??? Do the gun companies use MIM parts in repairs??

jj

[Sunray]

"...Do the gun companies use..." They use whatever parts they have. Just like military weapons techs.

[Just Jim]

"...Do the gun companies use..." They use whatever parts they have. Just like military weapons techs.

One would hope if you send back an old piece that they use original parts.

jj