Kimber1911_06238
Member
Can someone explain the lock and MIM for me? looked at their website but didn't find any info. they are putting integral locks in now? Thanks in advance.
Smith and Wesson (lock and MIM)
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Waywatcher
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Oh boy get ready, you just opened a big can of worms! 
MIM is metal injection molding, its a process they use to make parts such as hammers and triggers. It leaves tell-tale marks on the part and the QC is not quite perfect yet so you'll have bad ones and good ones. The ones that fail generally do so very early on in the life of the part.
The locks have a small keyhole in the side of the revolver next to the cylinder release. Insert and turn the key and a small flag pops up saying "locked" by the hammer. The trigger and hammer do not move then. There have been instances of them failing, mainly on the superlight scandium/titaniums firing magnum rounds.
MIM is metal injection molding, its a process they use to make parts such as hammers and triggers. It leaves tell-tale marks on the part and the QC is not quite perfect yet so you'll have bad ones and good ones. The ones that fail generally do so very early on in the life of the part.
The locks have a small keyhole in the side of the revolver next to the cylinder release. Insert and turn the key and a small flag pops up saying "locked" by the hammer. The trigger and hammer do not move then. There have been instances of them failing, mainly on the superlight scandium/titaniums firing magnum rounds.
RevolvingCylinder
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MIM also isn't generally as hard as forged or cast if I'm not mistaken.
RON in PA
Member
Actually MIM is harder. Nothing wrong with MIM, it doesn't look as nice, but the parts are produced with less variability making final assemembly easier.
The locks became standard in approximately 2002. This topic is highly controversal, do a search here and over at the Smith & Wesson Forum.
The locks became standard in approximately 2002. This topic is highly controversal, do a search here and over at the Smith & Wesson Forum.
EddieCoyle
Member
When done right (and S&W does it right), MIM parts are tougher than cast or forged parts.
The MIM process starts with powdered metal (mixed with a binder) that is injected into a mold (hence the name Metal Injection Molding). After molding the part is debound and sintered into a solid part. Because you can select mix metal powders with specific characteristics, MIM can produce a metal part with properties that you could never get by casting or forging.
Here's what I mean. With steels, "hard" and "tough" tend to be mutually exclusive. If you make a really hard piece of steel, it tends to be brittle. If you make a tough (hard to break) piece of steel, it tends to wear quickly. To try to get the best of both worlds, steel makers alloy other elements in with the iron. These elements (silicone, vanadium, chromium, etc) combine with carbon to make carbide particles. Carbide is very hard but also brittle. When the carbide content is low, these small carbide particles intersperse with the iron (like gravel in concrete) to form a steel that is tough but with little carbide wear surfaces interspersed throughout.
The tough part is getting the carbide particles to evenly disperse in the molten steel. If you try to add too much, the steel ends up very grainy. Here's where MIM really shines. With MIM, they can whip up a precise, even distributed mixture of hard and tough particles together, in exactly the proportions they want for the application. The finished part is much more consistent and predictable than what could be achieve with more traditional methods.
MIM gets a bad name for 4 reasons:
Like it or not, on production guns, MIM is here to stay. I actually prefer S&W revolvers that are pre-MIM, but I wouldn't refuse to buy a new gun that had it.
The locks just plain suck.
The MIM process starts with powdered metal (mixed with a binder) that is injected into a mold (hence the name Metal Injection Molding). After molding the part is debound and sintered into a solid part. Because you can select mix metal powders with specific characteristics, MIM can produce a metal part with properties that you could never get by casting or forging.
Here's what I mean. With steels, "hard" and "tough" tend to be mutually exclusive. If you make a really hard piece of steel, it tends to be brittle. If you make a tough (hard to break) piece of steel, it tends to wear quickly. To try to get the best of both worlds, steel makers alloy other elements in with the iron. These elements (silicone, vanadium, chromium, etc) combine with carbon to make carbide particles. Carbide is very hard but also brittle. When the carbide content is low, these small carbide particles intersperse with the iron (like gravel in concrete) to form a steel that is tough but with little carbide wear surfaces interspersed throughout.
The tough part is getting the carbide particles to evenly disperse in the molten steel. If you try to add too much, the steel ends up very grainy. Here's where MIM really shines. With MIM, they can whip up a precise, even distributed mixture of hard and tough particles together, in exactly the proportions they want for the application. The finished part is much more consistent and predictable than what could be achieve with more traditional methods.
MIM gets a bad name for 4 reasons:
- It's ugly. S&W even tried flash-chroming some MIM parts but the chrome didn't stick, making the parts even uglier.
- Early on, it wasn't always done right. Like anything else, there was a learning curve with MIM and some early parts were bad and broke.
- MIM parts have been misapplied. MIM is a lot of things but "springy" isn't one of them. When some 1911 manufacturers used a MIM extractor where they should have been using spring steel, the parts broke. Big surprise.
- It's new when compared to other processes, and it takes some people a while to accept it. These are likely the same people that in 1900, would have said that the metallic cartridge was a passing fad.
Like it or not, on production guns, MIM is here to stay. I actually prefer S&W revolvers that are pre-MIM, but I wouldn't refuse to buy a new gun that had it.
The locks just plain suck.
Kimber1911_06238
Member
are the locks only sent to certain states? I was looking at a NIB 686 only a few weeks ago and didn't see any lock hole? Is it just so small that I missed it?
cadfael
Member
All new 686's have the lock. It's a small hole directly above the cylinder release latch.
Adam
Adam
BADUNAME13
Member
The problem with MIM parts is that you can't do any filing... (Gunsmithing)
to the part as it is not one chunk of metal, and will basically loose it's temper and be destroyed. (Not right away...)
to the part as it is not one chunk of metal, and will basically loose it's temper and be destroyed. (Not right away...)
Master Blaster
Member
Actually thats not really true, some MIM is Homogenous all the way through, some is still case or surface hardened. Old parts that were cast or machined from barstock were soft so that they could take repeated impacts, hammers are an example of this. Then the wear surface, the single or double action notch was case hardened, or flash chromed so that it would have a hard wear surface and wouldnt easily wear out. If you file or stone one of the case hardened surfaces on the old parts, you cut through the surface hardening, then the part quicky wears out.
Many of the surfaces you would stone for a trigger job have a very close tollerence, and if you stone off 1/10,000 Its a good trigger job, but if you stone off 3/10,000 the part will fail quickly, irregardless of what it is made out of.
BADUNAME13
Member
I confess to not knowing gunsmithing.
I got the info from this guy: http://www.clementscustomguns.com/
I believe what you are saying is: That if you 'break through' the coating you will wear the part out very quickly.
-That matches up with what I was told, my appoligies for not saying it well enough apparently.
I got the info from this guy: http://www.clementscustomguns.com/
I believe what you are saying is: That if you 'break through' the coating you will wear the part out very quickly.
-That matches up with what I was told, my appoligies for not saying it well enough apparently.
fspitzdorf
Member
please correct me if i am wrong but with the 686, the -6 Rev incorporates the lock.
Best friend has a -5 (6 shot) with MIM hammer and trigger and NO lock...
My -6 + is a great gun... I HATE the lock but finding a good used older gun in these parts doesn't seem to be too easy... you just never see many 686 6"ers sittin in used gun cabinets...
The lock is pretty easy to disable if you really want to... since my 686 is a hunting firearm and a not a first line defense firearm I think when I get around to it, the flag is coming out of it... that just leaves taht unsightly slot next to the trigger...
My mod 60 (carry gun) has a lock also... the thought of removing it makes me uneasy... just due to the fact that there are too many opportunistic prosecuters out there should I "God forbid" ever have to use the gun in a self defense situation...
Best friend has a -5 (6 shot) with MIM hammer and trigger and NO lock...
My -6 + is a great gun... I HATE the lock but finding a good used older gun in these parts doesn't seem to be too easy... you just never see many 686 6"ers sittin in used gun cabinets...
The lock is pretty easy to disable if you really want to... since my 686 is a hunting firearm and a not a first line defense firearm I think when I get around to it, the flag is coming out of it... that just leaves taht unsightly slot next to the trigger...
My mod 60 (carry gun) has a lock also... the thought of removing it makes me uneasy... just due to the fact that there are too many opportunistic prosecuters out there should I "God forbid" ever have to use the gun in a self defense situation...
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