Who here has personally had a MIM part fail?

[ar15jules]

870 Extractor failure here. The gentleman who teaches my AR and 870 armorer's courses condemns MIM parts as the work of the Devil. He has personally worked at 2 large manufacturers and currently performs warranty work for a large manufacturer. I trust his opinion. In his last class I saw examples of MIM AR trigger groups.

[ChemDave]

Glock G21 extractor.

[DucatiRon]

Out of all the guns I own (that's alot but not as many a Cruzans) just 1 extractor on a Rem 1100 with about 250,000 12ga shells through it

[JenniferG]

MIM is done to reduce production costs.

While we would all love to see lovingly crafted, machined from pre-heat-treated bar stock parts in our arms, the need to produce these parts at prices that people can reasonably afford means that it is likely that the adoption of the MIM process by the firearms industry will continue to grow in coming years; some authorities estimate this at 20-30% over the next five years. Cost containment in a highly regulated industry, which is also constantly suffering from both legal and legislative onslaughts, is sadly here to stay. This is why most modern production arms makers have adopted the MIM process.

https://www.chuckhawks.com/metal_injection_molding.htm

[abner13]

MIM parts often have an approximately 1/8" circle somewhere on the part, left by the injection process. I say usually because I am guessing in some cases the circle may be removed in a final stage of manufacture, such as finish.

These are mold ejector pins marks. But they also appear on investment cast parts when the wax 'tree' parts are made in injection molds.

[Bang]

80,528 members, 15 replies, a few negative, a few positive. Maybe MIM parts are getting an undeserved bum rep?

[buckengr]

80,528 members, 15 replies, a few negative, a few positive. Maybe MIM parts are getting an undeserved bum rep?

Overall, I mostly agree that the automatic distrust probably isn't warranted, considering how widespread adoption of MIM is. I think there's more to it than simply parts being MIM in many cases. A lot probably depends on the company's individual QC, or lack thereof.

Anecdotal evidence being what it is, I'm not at all surprised to hear from others about problems with MIM parts from Remington and Sig.

But maybe certain kinds of parts with specific stresses aren't great candidates for MIM: extractors for example. For me personally, I know I don't want MIM extractors in my defensive shotguns if I have a choice.

[xXxplosive]

Talk about MIM's......RIA has'em.

[RockIsland]

Not me but when my kid was an RSO, he sent me a pic of a new Sig .22 that had the front 1" of the slide crack off.

I think I may have posted it here somewhere but I must have deleted it off of my phone.

[Bang]

Circa 2009, Beretta 92 and similar were experiencing broken slides. Have no idea if they were MIM'd. Likely not, but had they been, the blame would have been on the MIMing when it may have been the design even when executed in treated steel. A local range owner blamed steel ammo and bans it.