MIM Gun Parts Analysis - Under Microscope

SF0 · 10-01-2009, 11:55

Posted this for George Smith (EGW Guns) at another forum, and thought I'd post it here for informational purposes. I think this simply supports the common consensus here to buy the best weapons you can afford. For those that are unfamiliar, MIM stands for metal injection molded.

Pictures courtesy of George Smith at EGW.

Shops like Les Baer, RRA, and others that have had parts analyzed, refuse to use MIM.

Random porosity found on a mim sear section.

http://www.survival.host56.com/mimla...rositysear.jpg

Through porosity found on another sear. The long slices are hardness tester marks.

http://www.survival.host56.com/mimla...rositysear.jpg

Long void in another brand mim sear.

http://www.survival.host56.com/mimla...oidmimsear.jpg

Unrelated - Imported extractor made with what appears to be cold rolled bar stock with horrible voids running the length.

http://www.survival.host56.com/mimla...kextractor.jpg

Inside look at how MIM is actually made.

http://www.survival.host56.com/mimland/playdo.jpg

rubberneck · 10-01-2009, 15:37

George is my gunsmith and I am lucky enough to call him a friend. He has a sizable box in his shop of MIM parts that he has taken out of guns after they have failed. I always get a chuckle when people say that MIM parts are just as good parts made from barstock. They aren't. You might not have a problem with yours but you can bet that some where someone is.

SF0 · 10-01-2009, 17:34

For 1911's anyway, I purged any MIM guns from my inventory, and will only purchase future pistols from Les Baer, Wilson, Brown, or Dan Wesson. Indeed, there are a lot of people who have good performance from their mim filled guns, but if I can get forged or barstock instead, why not? Of course even those fail, but I see it as shrinking the chance of error.

st1650 · 10-07-2009, 13:39

Quote:

Originally Posted by SF0

For 1911's anyway, I purged any MIM guns from my inventory, and will only purchase future pistols from Les Baer, Wilson, Brown, or Dan Wesson. Indeed, there are a lot of people who have good performance from their mim filled guns, but if I can get forged or barstock instead, why not? Of course even those fail, but I see it as shrinking the chance of error.

No need to spend 3K, 300$ norinco 1911 are mim free.

Oldschool45B · 10-07-2009, 14:43

I am proud to call Bob and Jenny Greider a friend, and Greider Precision makes some of the finest 1911 parts in the world, for many high end pistol smiths (including all of those named here and many others). He was kind enough to sit me down one day (most of the day) and walk me thru the evils of MIM. Sadly many companies that once produced fine products are switching to MIM to save money and maximize their profit margins. I will never use MIM in a 1911 I build, regardless of it's end user or intended use. Frankly it is just shitty business to make a 1911 for LAPD and fill the gun with MIM.

Glad to see that someone has put the time into proving for the masses why MIM is shit.

dr. mabuse · 11-26-2009, 14:28

Haven't looked through a microscope yet, but I suspect that some of the parts on my Sig P250's are MIM, especially the extractor. Surface looks very porous.