MIM parts.

[aippi]

The issue of MIM Extractors in the 870 Express comes up often. People want to upgrade to the forged Extractor. I have even seen post on these forums where a guy says he bought the 870 Police because he doesn't want any MIM parts on his gun. Sorry guy, there are MIM parts in every 870 so your reason for buying the Police model was incorrect.

There are MIM parts in about every weapon we buy today. Here is list of what is most likely MIM on your favorite gun.

Hammer, Trigger, Front/Rear Sight, Safety lever, Catch Barrel, Plate Body, Extractor, Ejector, Disconnector, Sleeve Sight Stabilizer, Barrel Lock, Trigger Guard Sear, Locking Insert Bolt, Lever, Take Down Lever, Bolt Catch, safety levers, Slide Stop, Ambi-Safety, Grip Safety, Plunger tube and many more Componets.

Indo-MIM makes over 500 MIM parts that many US manufacturers use. So the chance that a modern gun you have bought in the past few years does not have some MIM parts is slim to none.

So to complain about a MIM part in an 870 seems silly to me when they are in about every modern firearm made today.

[spencerhut]

I have replaced many MIM parts on customer guns, most for no reason other than to fulfill the customers desire to have the MIM part removed. And I can't say I blame them. If you can afford forged & machined, then buy forged & machined.
I've seen everything break, don't matter how it's made, stupidity or wear & tear gets everything eventually.

[bigbearbear]

I'm surprised you posted this JD, I would think a misinformation like this in the market will give you a lot more business.

"Hey Mr. Keyboard Commando, you need to throw away those MIM parts used by sissies and have AI&P install forged ones like real operators do!"

[aippi]

The issue came up a day or so ago as it often does and I told the client that there is nothing wrong with a MIM extractor as I have never seen one fail. He then asked then why do you change them out.? I told him because he is paying me $800 for the shotgun. I then explained the only two parts that are different between the Express and Police and why I change them out. Which is because that what customers expect. I am unsure if the others guys even change out the Extractor and carrier dog follower spring as their web sites say nothing about it.

[BigFatGuy]

And yet, if you call it sintered people don't mind so much

[cgates]

I like to have the plunger and extractor blacked out and the MIM part wont take my cold blue. That's why I dump my MIM extractors on the 870s

[Mitch]

And yet, if you call it sintered people don't mind so much

Sintered is to MIM as polymer is to plastic.

[aippi]

Sintered is to MIM as polymer is to plastic.

There are people that complain about the Polymer Trigger Plate assemblies on the Express, Marine 870 and all the Tactical Models 870's but they have Glocks and other Polymer frame handguns. When the M-16 came out the troops called it the Plastic Fantastic because it had "Plastic" stocks, and now the AR-15 in all its forms is the one of the top selling rifles in the US. Glock manufactured 131,550 handguns in 2012 (2013 reports are not released yet but will be way higher then 2012). Looks like "plastic" is here to stay along with MIM.

[Steve_In_29]

Whether or not it was "metalurgically" related my friend's extraction issues with his 870 Express went away after swapping in a Wingmaster (forged) extractor.

[aippi]

Whether or not it was "metalurgically" related my friend's extraction issues with his 870 Express went away after swapping in a Wingmaster (forged) extractor.

Had nothing to do with it. However, he could have had a bunch of mess in the extractor spring channel and on the extractor spring plunger and in the process of the change he cleaned that mess out or upon removing the old extractor the spring cleared the fouling. The MIM Extractor is shaped perfectly and thus would more likely work better then the solid steel one.

Only three model 870's come with a solid steel extractor. Two are the Wingmaster and the Police and this is simply for Marketing. The third is the 870 Express Left Hand model as they don't sell enough of these to justify setting up the molding for MIM.

In the below picture the second from the left is the MIM and it is shaped perfectly. So perfect in fact that Remington now shapes the solid steel one ( first on left) as close as they can to the MIM. Most of you with a Police or Wingmasters older then a year have the old style Extractor (third from left) which has changed multiple times till they finally found a vendor to make one shaped exactly like the MIM one. Ignore the one on the far right as that is for an 11-87.

[Steve_In_29]

Well that being said, the shotgun boards are full of similar results from that extractor swap.

As far as the "bunch of mess" suggestion goes, my friend is the DEFINITION of the word "anal" as far as cleaning his weapons goes. Before he even fired the shotgun for the first time he had done a DETAILED cleaning that involved tearing it totally apart.

[aippi]

That is not all the boards are full of. Meaning they are full of misinformation.

I challenge anyone to explain why two dentical parts designed to perform the exact same task, a task as simple as hooking on to the rim of shotgun shell and pulling backwards, are going to perform different because they are manufactured differently.

Explain how that is possible and be specific and I will keep an open mind and may be persuaded. Until then I maintain there is no difference in the performance on the two parts.

[nhattran_1528]

At one point isn't the forged/machine extractor MIM when it started life as bare bar stock. Isn't most machined metal at one point started its life out as MIM. Either it was MIM into bar stock, cylinders, I beam, h beam etc!!!! Than cut down and machined into whatever we want it to be! So is a bar stock was incorrectly forged than cut down and machined into 870 police/wingmaster steel extractor. You than have a defective extractor!

[spencerhut]

That is not all the boards are full of. Meaning they are full of misinformation.

I challenge anyone to explain why two dentical parts designed to perform the exact same task, a task as simple as hooking on to the rim of shotgun shell and pulling backwards, are going to perform different because they are manufactured differently.

Explain how that is possible and be specific and I will keep an open mind and may be persuaded. Until then I maintain there is no difference in the performance on the two parts.

A bar of solid steel, cold or hot rolled, which is used to create "bar stock" parts is generally devoid of any porosity, i.e voids in the material.

Forged parts, parts which start out as hot or cold rolled steel and are then formed under extreme pressure are generally devoid of any porosity.

Sintered metal or Metal Injection Molded parts are generally more likely to have some, even if small amounts of porosity.

The porous nature of sintered or MIM parts gives rise to minor, though quite real additional failure points.

In my GSG STG-44 I could care less about MIM parts, it's a toy. In my daily carry CCW weapon it's Dan Wesson all the way.

[spencerhut]

At one point isn't the forged/machine extractor MIM when it started life as bare bar stock. Isn't most machined metal at one point started its life out as MIM. Either it was MIM into bar stock, cylinders, I beam, h beam etc!!!! Than cut down and machined into whatever we want it to be! So is a bar stock was incorrectly forged than cut down and machined into 870 police/wingmaster steel extractor. You than have a defective extractor!

I don't think you understand the process of making a forging vs a casting.