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1911 Parts: MIM vs Tool steel ?
- Thread starter J0RDAN357
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robmcd
Member
There are many MIM parts in the firearm industry, especially in more complex shapes that would otherwise be much more expensive to machine. Tolerances can be very precise. S&W uses many MIM parts (triggers, hammers, etc.), and the quality seems excellent. However, there are some other brands that use MIM parts extensively to save on cost, but their fit is not as exacting by comparison (i.e. Charter revolvers). MIM is here to stay.
Assuming that proper care is taken, there should be little difference in service. I have noted that the S&W MIM triggers have a case hardened skin that makes drilling for trigger stops impossible.
On the other hand, slight mistakes happen in either type of part. Rigid QC controls can minimize any ill effects.
Colts been using MIM fire control parts for decades (1911, AR series) etc.
On the other hand, slight mistakes happen in either type of part. Rigid QC controls can minimize any ill effects.
Colts been using MIM fire control parts for decades (1911, AR series) etc.
WaterburyBob
Member
For some reason I don't like MIM parts in revolvers, but I'm perfectly fine with them in semi-auto pistols.
Properly manufactured MIM parts are plenty strong enough and to my knowledge don't have a failure rate any worse than machined parts. Improperly made MIM will definitely fail more frequently. From my experience, S&W seems to be making very good MIM parts; I own a good number of their semi-autos and I have not had a single MIM part fail.
Properly manufactured MIM parts are plenty strong enough and to my knowledge don't have a failure rate any worse than machined parts. Improperly made MIM will definitely fail more frequently. From my experience, S&W seems to be making very good MIM parts; I own a good number of their semi-autos and I have not had a single MIM part fail.
shovelwrench
Member
Ive worked with some MIM parts in 1911s. Trigger jobs are made a little more dificult due to the casting lines and injector marks. They take quite a bit more stoning to get the mating surfaces smooth.
I'f you plan on going for a light trigger, say under 2.5lbs, I would advise against using a MIM sear. The bar stock they refer to is generally tool steel and VERY hard, holding a fine trigger job for a long time.
Most "drop in" trigger kits(hammer, sear combo) made of bar stock will give an excellent trigger job with very little work. (stoning hooks to .020, fallaway angle on sear, stoning sides of sear and hammer, and cleaning up disconnect)
I own a Kimber Pro Carry HD in 38sup that is full of MIM parts. 3.5lb trigger, stoned and polished internals, It was way more work then my target .45 w/ barstock internals and a 1.75lb trigger.
I'f you plan on going for a light trigger, say under 2.5lbs, I would advise against using a MIM sear. The bar stock they refer to is generally tool steel and VERY hard, holding a fine trigger job for a long time.
Most "drop in" trigger kits(hammer, sear combo) made of bar stock will give an excellent trigger job with very little work. (stoning hooks to .020, fallaway angle on sear, stoning sides of sear and hammer, and cleaning up disconnect)
I own a Kimber Pro Carry HD in 38sup that is full of MIM parts. 3.5lb trigger, stoned and polished internals, It was way more work then my target .45 w/ barstock internals and a 1.75lb trigger.
torrejon224
Member
There us so much debate over this that it drives me crazy. I have never or should say rarely heard of MIM parts breaking in a gun, with todays technology they are fine. If your building your own 1911 for example then by all means go for the tool steel hardened parts as there only a few dollars more but to buy a gun and then completely replace all the MIM parts is just crazy IMO.
shovelwrench
Member
I agree, but there are is more work involved in a trigger job when MIM is used, in a 1911, I've never worked on a MIM revolver.
BUT cast is never as hard as tool steel, although tool steel very well might be overkill.
mim parts
look i am by no means an expert....however, i have a Smith and Wesson 1911 and the mim parts that i am reading that everybody loves are horrible....look if ya shoot 100 rounds a year i am sure they are fine but frankly i shoot quite a bit and the so called mim parts have failed...broken...whatever 14 times in the last two years. I am not allowed to put hardened parts into the gun cause it will void the warranty, (I am a cop). Have fun with your mim parts my personal guns all have hardened parts. Let the hating begin!
look i am by no means an expert....however, i have a Smith and Wesson 1911 and the mim parts that i am reading that everybody loves are horrible....look if ya shoot 100 rounds a year i am sure they are fine but frankly i shoot quite a bit and the so called mim parts have failed...broken...whatever 14 times in the last two years. I am not allowed to put hardened parts into the gun cause it will void the warranty, (I am a cop). Have fun with your mim parts my personal guns all have hardened parts. Let the hating begin!
CAJUNLAWYER
Member
Will it void the warranty if you're not a cop???look i am by no means an expert....however, i have a Smith and Wesson 1911 and the mim parts that i am reading that everybody loves are horrible....look if ya shoot 100 rounds a year i am sure they are fine but frankly i shoot quite a bit and the so called mim parts have failed...broken...whatever 14 times in the last two years. I am not allowed to put hardened parts into the gun cause it will void the warranty, (I am a cop). Have fun with your mim parts my personal guns all have hardened parts. Let the hating begin!
BTW...what parts have broken 14 times over two years?
BruceM
Member
Roger that!
I would really like some documentation on this as well.
Bruce
BlueOvalBandit
Member
This has been my experience with mim hammers when bobbing them and hollowing them internally. I barely scratched the surface breaking 3 bits of various types (HSS, TiN HSS, and Cobalt) before I stopped messing around and broke out the $65+ Tungsten carbide drill bit. I skipped the dremel and finished the job with carbide burrs and a pneumatic die grinder I used for engine work.
TAROMAN
US Veteran
In my experience, S&W revolvers with the MIM internals feel smoother and more precise out of the box. I've never had a MIM part break, or even heard of such.
Only revolver breakdown I ever experienced was the bolt in my Model 60-0 snapping in half. Luckily, that happened at the range:
If a LEO broke 14 MIM parts, it was likely from something other than normal use, IMHO.
Only revolver breakdown I ever experienced was the bolt in my Model 60-0 snapping in half. Luckily, that happened at the range:
If a LEO broke 14 MIM parts, it was likely from something other than normal use, IMHO.
Sounds like the MIM parts are plenty hard then after all.
I don't think that statement is true.
Brownells has everything you will need for the 1911, listing bar stock and MIM parts.
The 1911 is a tricky gun to work on if you have no idea (novice) of what you are doing. You don't want to install something then have the hammer follow home when you close the slide, nor do you want the hammer to fall from full cock when you disengage the thumb safety, etc., etc., when you put different parts in the gun.
I would not hesitate to buy Cylinder & Slide's complete hammer/sear/disconnector/hammer spring kit that is already assembled/fitted as a unit (near drop in........although advertised as drop in, some fitting may still be required) and have someone help you install the kit if need be. The parts in the kit are "certified" by C&S to a specific hardness. It all depends on what 1911 you want to have worked on and how far you want to go...$$$$$ wise.
Whatever you do, make sure all the safties function properly afterwards and that you don't opt for too light of a pull for defensive use.
TAKJR
The 1911 is a tricky gun to work on if you have no idea (novice) of what you are doing. You don't want to install something then have the hammer follow home when you close the slide, nor do you want the hammer to fall from full cock when you disengage the thumb safety, etc., etc., when you put different parts in the gun.
I would not hesitate to buy Cylinder & Slide's complete hammer/sear/disconnector/hammer spring kit that is already assembled/fitted as a unit (near drop in........although advertised as drop in, some fitting may still be required) and have someone help you install the kit if need be. The parts in the kit are "certified" by C&S to a specific hardness. It all depends on what 1911 you want to have worked on and how far you want to go...$$$$$ wise.
Whatever you do, make sure all the safties function properly afterwards and that you don't opt for too light of a pull for defensive use.
TAKJR
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ILLWIND
Member
My take on this issue as a S&W owner and precision machinist for the last 30 yrs; There has been huge improvements in MiM manufacturing. It used to be a similar process called sintering, which for the most part in my experience is junk. With MiM / permanent die parts becoming a popular manufacturing alternative in the last decade or so they have been even used for connecting rods in car engines. But, I have never heard of a TOP Fuel dragster using MiM rods (8000+ Horsepower)
My experience is that forged parts that are PROPERLY machined/heat-treated are still superior to MiM. In the hammer/sear relationship,IMHO, the tool steel parts hold their precision wear surfaces longer.
MiM parts generally are a cost saving measure...less time on a precision machine tool is LESS money spent, larger room for profit, more parts with fancy contouring & intricate details can be had for less money per part with MiM.
My experience is that forged parts that are PROPERLY machined/heat-treated are still superior to MiM. In the hammer/sear relationship,IMHO, the tool steel parts hold their precision wear surfaces longer.
MiM parts generally are a cost saving measure...less time on a precision machine tool is LESS money spent, larger room for profit, more parts with fancy contouring & intricate details can be had for less money per part with MiM.
