What parts on a Springfield 1911A1 are MIM?

[Old Sarge]

Hi All
I am thinking of getting a Springfield 1911A1 to use as the base for a buildup pistol. Some one told me that there are a bunch of MIM parts in it that I would want to replace. First off what is a MIM part and which ones are they on a Springfield Basic? The slide and receiver are forged as I understand it?

Thanks
Old Sarge

[Rustolium]

MIM is Metal Injection Molding, like how the mold plastic. From what I understand, they are about the same quality as machined parts. They are better than cast though. Just going by what I have heard, I have no first hand experience, as far as I know.

[Bryan 45]

I would expect this to get into a long, drawn-out, heated debate.....

My opinion-- There's nothing wrong w/ MIM. By a new gun, fire a couple hundred rounds, if nothing breaks, it's not going to. MIM parts that have issues almost always break right off the bat. I had a firing pin safety in a Kimber that broke in half. Gun wouldn't fire, but it was within the first 100 rounds. Kimber fixed it under warranty.

I've never seen the logic in buying a new $600 pistol and spending another $300 on replacing the parts. If a Springfield breaks, they will fix it.

Just my 4.6 cents, adjusted for inflation.

[molonlabe texan]

The only parts of a 1911 that would worry me are the extractor, the hammer, sear and disconnect and of course firing pin. Those should all be good hardened tool steel regardless of what weapon you have.

[Pluskat]

Not saying they aren't, but since when is SA using MIM? My MilSpec is about 9yrs old so they COULD have changed their practices but it would surprise me if they did.

FWIW- My MilSpec is a daily work/carry pistol that has held up to double-digit thousands of rounds with only one broken part...the firing pin stop cracked but was noticed before it could break. In all fairness, the gun's hardly stock but all parts replaced were done for strength/reliability (real or hoped-for) and highly tuned by my GS. I call it a Chevette with a Ferrari engine. IMO, the MilSpec is an excellent place to start as a project. It allows you to have an immediately carryable firearm that you can "tweek" as money/research/time allows.

Have fun.

[TerryN]

I suspect that a lot of the bad press that MIM (and cast) parts get is generated by people who sell aftermarket replacement parts. I chuckle when I see people buy a Springfield 1911 or M1A and rush out to double their investment by replacing every moving part with aftermarket forged, or USGI milsurp parts (in the case of the M1A).

Ask them 'why,' and they'll say 'coz some guy on (fill in the blank) forum said MIM (or cast) parts are junk!'

"Have you shot that gun?'
'No.'
'Then... how do you know you'll have problems?'
'Coz some guy on (fill in the blank) forum said MIM (or cast) parts are junk!'

If I were a firearms manufacturer, why in the world would I sell guns with junk parts in them? Assuming that I wanted to stay in business, at any rate.

Now before someone mentions Hesse and a few others, I think we'll agree that those companies are the exception, rather than the rule.

Me, I'm going to give Springfield the benefit of the doubt, and at least fire the gun before I assume that I need to replace every moving part in it.

Just MHO. Buy the gun. Shoot it. A lot. Then decide if it needs any work. And remember, that's what a warranty is for!

[whirlibird]

Originally posted by Old Sarge
Hi All
I am thinking of getting a Springfield 1911A1 to use as the base for a buildup pistol. Some one told me that there are a bunch of MIM parts in it that I would want to replace. First off what is a MIM part and which ones are they on a Springfield Basic? The slide and receiver are forged as I understand it?

Thanks
Old Sarge

Good place to start. The Mil-Spec's and GI WWII models are the best bang for the buck out there.

If I were building a work-piece out of either, I'd start by changing out the mainspring housing for one without the danged safety garbage. This requires the replacement of the hammer spring and the plungers also.
No chance of the gun being 'accidentally' being on safe when I need it.

The disconnector and sear are MIM parts, they go in the trash. Brown or Wilson parts are the usual replacements. $40 in parts, big deal.

A switch to an 18 1/2lb recoil spring is recommended for "duty" loads, especially the +P JHP's. A whopping $8.

I like to change the old flat thumb safety out (rounded on current models) for an extended model or a Colt standard thumb safety. $25-50

After that, most everything is personal preference.
I prefer (require) long triggers and flat mainspring housings, basic mods that make it more efficient for me.

The more you screw with it, the more chances it's gonna muck up. Shoot it, find out what you, not some other guy need and then stop there.

And this is from a guy who used to make good money building these things.
K.I.S.S.

I've owned a dozen or better Springers over the years and with minor touches, they've been 100%, can't say the same for other brands except Colt (with the same touches).