AUUGH! S&W Wants to put MIM in my nice pinned and recessed M19!


November 13, 2006, 04:19 PM
OMG- sent my beautiful old P&R Model 19-4 in for repair coz someone had smithed it to the point where it wouldn't fire reliably. in double action.

1st piece of bad news: Need new cylinder, (all chambers expanded) that's a hundred more bucks that I wanted to spend.

2nd piece of bad news: they want to replace the trigger becasue it was altered... with a MIM one! At least the Hammer assebbly isn't, I don't think... says "HAM ASSY 375 BL"

Egads. I don't want MIM in my nice old gun. Also not ready to shell out $230 to do that either.


any advice?

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November 13, 2006, 04:39 PM
S&W wants to put MIM parts in because that's what they have now. If you can find a used hammer in good condition and send it to them they might be willing to use it - and they might say that trying to get the hammer and your gun to the same gunsmith at the same time is beyond their abilities.
Here are some links to let you try and find a forged hammer.

Jack First Gun Shop (
http://Numrich Gun Parts (
Western Gun Parts (

November 13, 2006, 05:13 PM
Call Century and order one of these kits:
(I believe that the hammer and trigger is compatible with the M19 because they are both 'K' frames. While the included hammer is double action only with no hammer spur, the trigger is complete, not MIM, and has the single action sear. The cylinder would NOT replace the M19s though because it is for .38 special only.)

I think SOG and J&G sales may also have these kits - but Century has the best price. I bought 2 of them from Century just last week:


CSA 357
November 13, 2006, 06:15 PM
please dont let them do that, find some used parts:fire:

November 13, 2006, 06:15 PM
I'm not sure what MIM means, but I take it they want to put in an newer part of some sort. Also not quite sure what you mean by the chambers being "expanded." The gun wasn't reliably firing the cartridges you were putting in; how does that work into a new cylinder and the other replacements?

November 13, 2006, 06:21 PM
I'm not sure what MIM means,
Metal Injection Moulding. Powdered metal is injected into a mould with a binder and formed into the shape of the part using heat and pressure.

Some people don't like MIM parts. I prefer regular ones, but I don't absolutely reject MIM.

November 13, 2006, 06:47 PM
Expanded chambers means some overly hot loads were run thru that revolver and buldged the chambers (not always seen but it can be measured). Since the cylinder is now out of spec it should be replaced.
Since M19-4s are P&R you are lucky they have the longer cylinder.

November 13, 2006, 07:45 PM
The MIM parts should be plenty strong... after all, our military's fighter jet engines are MIM-made.

That said, all Smith & Wesson Performance Center handguns use forged hammers and triggers, so it is not true that they don't have forged parts laying around. Now, the PC is considered a separate unit, so you might have to send it to them and they may want more money... but they should have forged triggers in the PC in abundance.

November 13, 2006, 08:20 PM
The MIM parts should be plenty strong... after all, our military's fighter jet engines are MIM-made.

Yes, and the QC/QA process involves some non-destructive test methods that if done with a pistol part would make the MIM part cost more than previously more expensive forged or machined part. MIM works fine provided 1) It's done properly, and 2) The part was designed taking MIM's attributes into acct. Those jet engines were designed knowning MIM parts would be used. Pistols like 1911s and P&R S&Ws were designed when parts were machined from stock or forged, because those were the only ways to make them. I know from reading posts by Tuner and Fuff that some 1911 parts simply do not work if made by MIM because the properties inherent to the manufacturing process vary too much from the properties of an original spec machined from stock part. I'll wait and let Old Fuff and the expert revolver smiths here weigh in on MIM parts for S&W wheel guns. Personally, I'd ask S&W to return the gun as is. I'd then go to the American Pistolsmiths Guild website and find someone who specializes in S&W revolvers. I'd send the pistol them with used or new old stock machined parts, and have them fix it. They might also have the parts on hand in their benchstock too. I hope everything works out on your S&W.

Old Fuff
November 13, 2006, 09:11 PM
Try Numrich/The Gun Parts Corp. at (

They also have the "everything but the frame" kits for K-frame .38 Special revolvers, and the hammer spurs are usually intact. But that said, they also have hammers and triggers as a seperate item, and one made for a model 19 (first choice), model 15 (second choice) or model 10 (third choice) would work. Usually they supply a used hammer or trigger removed from another gun - but they may have new ones also - it doesn't hurt to ask.

They might have a cylinder with recessed chambers, again taken from a scrapped gun. A lot of police departments used to send in guns that had been confiscated, or their own that under regulations had to be destroyed. Numrich would remove the good parts, pay the department for those parts, and then return the frames for destruction to make the anti-gun folks feel warm and fuzzy.

Understand, these are not something you drop in unless lightning strikes. You would probably need a qualified gunsmith to install them.

The MIM trigger will work. The hammer won't. I too would like to keep a 19 as original as possible, but this is an excellent example of what can happen when somebody decides to do their own action work. If the gun is returned to the factory for any reason they'll replace all of the "worked on" parts at the owner's expense. The company lawyers insist on it.

Also if you buy a cylinder be sure the original extractor comes with it. Extractors do not interchange between cylinders.

Also, those who are determined to extensively fire the hottest of the hot .357 Magnum loads through a K-frame or lighter revolver might take note about the part concerning expanded chambers... :scrutiny:

November 13, 2006, 09:39 PM
all Smith & Wesson Performance Center handguns use forged hammers and triggersI only own one Performance Center revolver, but it has a MIM hammer and trigger.

Qualified Gunsmith? Grant Cunningham ( I'm not sure I would be willing to drop $250 into a Model 19-4 either.

November 14, 2006, 07:31 AM
One should be a little circumspect in assuming all MIM is inferior just because one manufacturer has had issues. You just don't hear much about that nasty S&W or STI MIM.

Relax, breath slowly and deeply, into a brown bag if necessary. Hyperventilation can impair judgement. It's MIM, not the end of days. :)

cortez kid
November 14, 2006, 10:34 AM
I wouldn't worry about it. If it's got concerns like blown cylinders and mangled hammers and triggers, I would get it repaired and look for another one in great condition to hold. Shoot this one and pass the other to your Grandkids. See if you can get Smith to put one of their trigger jobs on it and enjoy.

Jim Watson
November 14, 2006, 10:50 AM
I am with Cortez Kid. Let S&W return it to shootable condition. Since money seems to be an issue here, you do NOT want to go with the custom gunsmith and scrounged milled parts route. It could be made as good as new or better. But it would be expensive with a capital $.

November 14, 2006, 12:55 PM
Thanks for the replies, all!

Heck, for the $260 price tag I can get another M19 2.5" at a store I know of. Kind of beat up, but maybe if I can strip the parts off it...

I just want to keep a neat gun more or less original.

This gun must have seen some serious use before I got ahold of it if the chambers were all expanded. That would explain the cracked brass I've had in that gun one time. For the record, it wasn't me that "gunsmithed" it to death.... must have been one of the previous owners.

It's not that it doesn't fire now, it's just that it sometimes doesn't. Single action, it fires all the time, because the hammer goes back another fraction of an inch. Double action, not so.

I dunno, I might have it just sent back and pick up the 19-6 I've had my eye on for the same price as it would be to repair this one.

Old Fuff
November 14, 2006, 03:07 PM
It is sometimes foolish to draw conclusions when you can't actually examine a gun. S&W of course has, and they might have found something that hasn't been mentioned here. But with a full understanding that I might be all wet, I'll offer the following observations:

When a revolver will fire reliably in the single-action mode, but not double-action, the reason can usually be traced to three reasons (sometimes combined).

1. To get a light trigger pull some inexperienced person has fooled with the main and rebound slide springs to lighten them, and/or shortened the mainspring strain screw. The solution is to replace the questionable springs or screw with correct ones. This is reasonably inexpensive.

2. The cylinder has developed a condition called "end shake," which is back and forth movement, as opposed to rotational movement. Given that the cylinder apparently has expanded chambers, caused by firing too many hot loads, the likelyhood of end shake is very possible. Again, correcting it is usually not expensive.

3. The tip of the hammer nose (firing pin) is shortened or broken. Again, replacement of it and a new rivet is not especially costly.

Unless someting radical was done to the trigger, that - in and of itself - should not effect double-action ignition, and while expanded chambers represent a serious issue, they too wouldn't effect double-action ignition.

It would seem that S&W has found, and addressed a number of conditions, but not necessarily the one that caused the revolver to be returned in the first place.

November 14, 2006, 04:00 PM
Old Fuff, there is nobody better than you. :) I replaced the main spring myself already in hopes of correcting the problem, but it did not help. I know the strain screw is in as tight as it can go, but I didn't think about it being shortened. There is a small amount of end-shake, but not more than you find among the usual run of used revolvers.

I had guessed that the reason it had light strikes was that the hammer has been bobbed, and was missing the necessary mass to make the impact hard enough, so I assumed that putting a spurred hammer on would restore it to working order, but like you, I may be all wet on that. I think I will have it returned, buy the 2.5" 19-6 that I have my eye on ($275 with beat-up bluing) and maybe start playing with finding another used hammer and strain screw from your excellent links.

One more question in addition to the hammer mass question (which I implied but never actually asked ;) )... i've fired this thing plenty of times with no ill effects except for some cracked S&B brass one time. Is it safe to keep this as a woods/range gun, or am I risking barrel rupture one of these days? (assuming I stick to safe loads)

Old Fuff
November 14, 2006, 04:42 PM
If the mainspring and strain screw are stock there should be enough mass in the hammer to insure ignition, even if the spur has been cut off. This presumes that everything else is right - don't forget that cylinder end-shake increases headspace, and a little can go a long way. Also there is always a chance that the hammer nose (firing pin) is short. Shouldn't happen, but does. I would have considered the possibility of a streached frame, but if that was the case S&W should have found it.

If the cracked cases were limited to one brand of ammunition I wouldn't worry unless the same thing started to happen with different brands. Unless the cylinder was replaced I wouldn't carry that particular revolver as a weapon, but otherwise... yes. Stick to less then magnum loads.

Do keep in mind that a used but sound cylinder assembly, as well as a trigger (and/or hammer) from would likely cost far less then buying a complete revolver to salvage a few parts.

November 14, 2006, 06:18 PM
It's not that it doesn't fire now, it's just that it sometimes doesn't. Single action, it fires all the time, because the hammer goes back another fraction of an inch.
What happens if you just put in a new mainspring? BTW, is Smith still making stainless springs or are they standard steel? All my old stainless guns had stainless mainsprings. They also had flash chromed hammers and triggers. I really hate them using non-flashed hammers and triggers.

I also would think any strain on a gun bad enough to cause expansion of the chambers would also loosen the gun, especially an M19.

January 8, 2007, 01:00 PM
Thanks to some very generous people here and on other gun boards, I got a number of nice used parts, and also got my M19 back from S&W unmolested.

I bought a new (old) hammer and hammer spring screw from Numrich, installed them today, and there is much improvement! It turns out that I was wrong, the hammer spring screw HAD been shortened a bit, and that's why the hammer was falling withough much force. (I bet, anyway). When the weather gets a bit better, I'll go out and test it. :)

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