I see many suggestions to change the extractors and slide stops on SA 1911-A1.
I have a SS Custom Loaded. Are there any parts I should change? Are the changes just necessary on the blued pistols or on the MilSpec pistols?
Are there MIM parts on a SS pistol?
Thanks,
Jim

Here is a list of the MIM parts in your SA 1911A1.

I have to give Hobbs credit for giving me this list.

-firing pin stop
-barrel bushing
-extractor
-ejector
-hammer
-sear
-disconnector
-thumb safety
-grip safety
-mag release
-slide stop


Hopefully that will help you with what you are looking for.  One of my 1911's is a SA 1911A1.

They make stainless steel MIM parts?
Jim

Yep

Most of the pieces you can easily see molding lines in if you look at them close enough.

Why change em out? Why fix what’s not broken?  I have had my two Kimbers for over 7 years and they run great.  I have not changed a thing on them other than the trigger and the mainspring housing.    I think it’s weird how people will bash MIM parts on a 1911.  Sig and other gun manufacturers use MIM and nobody complains about their parts.

Quoted: Why change em out? Why fix what’s not broken?  I have had my two Kimbers for over 7 years and they run great.  I have not changed a thing on them other than the trigger and the mainspring housing.    I think it’s weird how people will bash MIM parts on a 1911.  Sig and other gun manufacturers use MIM and nobody complains about their parts.

Some people take the MIM thing to the extreme.  Thee are two considerations with MIM parts in a 1911.  The first thing you have to ask is "will I be staking my life on this gun?"  If the answer is no, then it's truly a non issue.  The second thing is, "if MIM parts are inferior, which parts are really affected?"

The second question is the one most people seem to miss.  There are a lot of MIM parts in a Kimber or Springfield.  Few of them are high stress.  The slide stop and hammer are the parts that see the most stress and will for sure cause a stoppage if broken.  MIM ambis have a tendency to break at the joint, and that could ruin a person's day.  Other parts that are high stress but are much less prone to cause a stoppage are the firing pin stop and the ejector.  Parts like the extractor, sear and disconnector rarely break, MIM or not.  Other items, like the barrel bushing, the gripo safety, the mag release, etc. are non issues, though there might be an occasional freak breakage out there.  This is also bound to happen with cast, forged and barstock parts.

My guess is people would complain about MIM parts in Sigs and other manufacturers if they were originally made with barstock and to cut costs they were currently made with MIM parts that have shown a history of pre-mature breakge.  MIM technology is not really the problem though.  It's poor execution by the vendors that supply Springfield and Kimber.  I've learned a lot of information lately from my father in law who is a metalurgical engineer.   His team at work designs military helicopter engines, and they use MIM for some very critical high stress parts.  He knows all about metal stress, which is his specialty.  I'm looking at MIM in a whole new light, and I'm conviced that wherever Kimber and Springfield get their MIM stufff, it's low quality.

I may just wait until something breaks and replace it with a non MIM part. Unless I run across a good deal on some of the more critical parts.
I have already replaced the arched mainspring housing with a flat one without the ILS. It's also got the SA target sights.
Do the ambi safeties break often?
Jim