Comparing a S&W revolver made with MIM parts to a revolver made with machined parts

[Vodoun da Vinci]

Driftwood, I have followed this thread a bit and noticed many have already said it but I could not refrain from thanking you for the intensity and presentation of this thread. It's rare on the discussion forums to find something this powerful and informative and I'm very impressed and grateful for your taking the time to do all the legwork on this in our behalf. Pictures and dis assembly and all that is frankly stunning.

I'm not worthy. Need an icon for that here. Thank you so very much.

VooDoo

 

[Iggy]

I have read this thread with great interest and really appreciate the effort Driftwood has put into it.

Very very informative, and the comments have been helpful too.

My compliments to all.

 

[Driftwood Johnson]

Howdy all

Many thanks for all the kind comments.

However I respectfully repeat the request I made at the beginning of this thread that others refrain from posting photos to this thread.

I realize I do not 'own' this thread, and I have no authority to prevent others from posting photos. It is just a request. I would like to keep the photo content being created in this thread to the photos I took for this little project. So I respectfully ask that others honor my request.

I do welcome all constructive comments from all knowledgeable contributors. I have already learned much about the subject from others who have corrected my errors, and those who made additional remarks.

Thank you.

 

[Driftwood Johnson]

Cylinders

It is time to leave MIM land now. I believe all the parts of the cylinders are traditionally forged and machined.

Earlier I remarked that the assembly numbers on the yokes suggest to me that there was some custom fitting done to these parts so they could be returned to their respective frames for final assembly.





There is a bit of rounding off evident at the end of the Stainless yoke of the Model 617. It appears to have been done by hand. Also, notice the different shape of the reliefs on the yokes that receive the front side plate screw. The relief is 'U' shaped on the Model 17, it is a 'V' on the Model 617.





Here are the screws the way it used to be done. Obviously this is a Three Screw frame. Five and Four Screw frames were a bit different in the shapes of the 'extra' screws. A discussion for another time. Whenever I take apart an older Smith I always try to keep track of exactly where each screw went. As can be seen in this photo, the front and middle side plate screws are identical. I have read that at one point the front side plate screws were cut to length so they could be screwed in all the way and the yoke would not bind. I do not know if this is true. I have run across revolvers where the front screw would bind the yoke if the screw was driven all the way home. Whether or not the screw was in the wrong hole I do not know.

With Three Screw revolvers like this one, the screw under the top of the grip has the head cut straight across, and when torqued in all the way the head is subflush to the side plate, so it does not interfere with the grip. The other two screws have slight domed heads and they typically project a few thousandths above the side plate.





Here is the arrangement for the side plate screws of the Model 617. Way back I mentioned that the hole in the side plate for the front screw is a larger diameter. Here is why. The screw has a 'V' point to match the 'V' groove in the yoke. The thread is a larger diameter than the other two screws. And there is a locking patch on the screw to keep it from backing out. When this screw is torqued all the way in, it does not bind the yoke.

The heads of the other two screws are dome shaped. Interestingly enough, the front and middle side plate screws sit slightly proud of the side plate when completely torqued in. But the counterbore of the screw under the rubber grip is deeper, and the head sits subflush. A nice touch, simple enough to do with the CNC code, but I don't really see why since the rubber grip would yield to a slightly proud screw anyway.







The rears of the cylinders are quite different. Besides the obvious fact that one is a six shooter and the other is a ten shooter. The 'ratchet teeth' (that's what I always call them) on the extractor are quite different in shape.

Notice the lack of the small guide pins on the 617 cylinder. Smith and Wesson almost always used guide pins to align the extractor to the cylinder. Usually pairs. Yes, I just checked my Model 1896, and it lacks guide pins. Notice how the 617 cylinder uses the shape of the extractor to line it up with the cylinder, in lieu of pins. Another example of less parts, and less complicated assembly.





This photo is a little dark, but the guide pins are plainly visible.





And the pins are lacking in the 617 cylinder.

These photos also reveal another interesting detail. You have to look closely, but there is a narrow slot milled into the extractor rod of the Model 17, and a tiny tab on the cylinder that rides in the slot. These are the features that prevent the cylinder from rotating independently of the extractor while ejecting empties.

Notice there is a relatively broad flat milled onto the ejector rod of the Model 617. There is a corresponding flat in the hole in the cylinder.

Now, as far as I know, it is still impossible to drill a hole that is not round. I suspect the hole in the cylinder for the Model 17 may have been broached to achieve the little tab in the hole. I wonder if the flat in the hole of the 617 cylinder may have been cut by Wire EDM? I do not know the answer to that.

 

[Jim K]

I guess everyone is tired of me by this time, but maybe once more ...

The new front sideplate screw is not solid; it has a spring inside and a conical plunger that fits the "V" in the new type crane. To do that, they had to make the screw larger. That is a more complicated system (they "borrowed" the idea from Colt) but makes assembly easier by not having to file one side of the old type screw to fit.

The rear screw was made with a flat head when they went to Magna stocks; they first tried drilling a "dimple" in the stocks, but eventually went to the flat head screw. With rubber grips, there is enough "give" that the round screw head doesn't matter. And if they countersink it, even better; again a minor change in making the sideplate, while making assembly easier by not having a special screw.

Jim

 

[MrBorland]

The new front sideplate screw is not solid; it has a spring inside and a conical plunger that fits the "V" in the new type crane. To do that, they had to make the screw larger. That is a more complicated system (they "borrowed" the idea from Colt) but makes assembly easier by not having to file one side of the old type screw to fit.

IMO&E, this new "V & plunger" design further weakens the Achilles Heel of the S&W revolver, and it's this change that's had a bigger effect on "overall performance" than any of the MIM parts.

Since the yoke screw is the only thing keeping the entire cylinder cylinder assembly from sliding off the front of the gun, the V-grooved yoke and plunger screw make it easier for the gun to go kaput during a reload. I've seen it happen numerous times. And depending on the kaput-ness, a trip back to S&W may be required.

For the handy, carefully fitting a solid pin to replace the screw's plunger spring greatly strengthens this area.

 

[StrawHat]

When S&W first made revolves with the swing out cylinders, they did not use pins to align the extractors. Instead, the arms of the extractors were fitted to cutouts in the cylinder. No pins needed! The pins were originally used to simplify manufacturing and cut costs. Now, the pins are gone and the extractor is cut to fit the cylinder. Everything old is new again.

Kevin

 

[MrBorland]

Now, the pins are gone and the extractor is cut to fit the cylinder.

I think, this is an example of a good change, from both a manufacturing and performance perspective.

Unless the pins remain perfectly in line with their corresponding holes, reset of the ejector star can be sluggish, and can affect the action. With a re-designed ejector star, the pins aren't needed, so it's a simpler, more reliable approach.

 

[ApacheCoTodd]

It's interesting to "watch" this.

A great example of showing "MIM" more as a period of production than merely a manufacturing option. Noting the tangental/peripheral/complimentary alternative manufacturing steps which accompany the MIM made guns is at least as interesting as the MIM itself.

I wonder if we'll be around long enough for the MIM period to elicit sentimental notes of: "Yeah, the new one, it's a good pistol but back when S&W used MIM, that was a sweet gun!"

Thanks for the post DJ.

Todd.

 

[Driftwood Johnson]

Thanks to Jim K again, for pointing out to me that the front side plate screw had a spring plunger in it. Did not know that. Just checked, and sure enough, the spring is very light, the 'V' plunger presses in very easily.

Can't speak about malfunctions where the spring allowed the cylinder to come loose.

 

[Driftwood Johnson]

Winding down now, almost done with my photo essay.

Markings

Like most firearms manufacturers, Smith and Wesson has always used roll engraving to mark their firearms. A hardened roller with raised features for the markings is rolled under pressure across the workpiece to imprint the markings on the steel. When this is done, the pressure usually raises small amounts of metal on the edges of the markings. One of the ways to tell if a firearm has been refinished is to check to see if the edges of the markings are still raised or have been polished away.

Although the characters are slightly smaller on the Model 617, the four line address on the right side of the frame is pretty much the same on the Model 617 as on the Model 17.








While not as elegant as the markings on the barrel of the Model 17, the markings on the barrel of the Model 617 have also been roll engraved. Yes, the Smith and Wesson name and caliber markings have been switched on the Model 617.











So after spending just as much money to roll engrave everything else on the Model 617, the logic of why Smith and Wesson chose to laser engrave the S&W trademark on the 617 escapes me. Perhaps they were after the 'gold' appearance. To me, it just looks cheap and cheesy. Sorry for letting in that obviously biased opinion. Of course in all fairness, I did not realize the trademark had been laser engraved until I took a look at my close up photos.








Just grabbed the 617 and took another look. Yup, even with my bad eyesight it is obvious the trademark has been laser engraved. Go ahead, call me a purist.



P.S. Here is an afterthought. Laser engraving works best on flat surfaces, so the laser can be in focus across all the markings. Perhaps that is why all the other markings on the 617 are roll engraved.

 

[Jim Watson]

When this is done, the pressure usually raises small amounts of metal on the edges of the markings. One of the ways to tell if a firearm has been refinished is to check to see if the edges of the markings are still raised or have been polished away.

Once upon a time, the factory applied the roll marks, THEN completed polishing and bluing the gun, giving a smooth level appearance. Only fairly recently have they been marking after what now passes as polish and leaving the cratered stamps. Colt is worse than Smith.

 

[Jim K]

Hi, Mr. Borland,

I have a couple of S&W revolvers with the new type front sideplate screw, and after reading your post, I tried getting the cylinder to fall out as you described, but was unable to do so. One yoke moved forward a bit under a lot of pressure, the other didn't. It looks to me as if the idea is that if the screw is turned in all the way, it butts the conical plunger and won't allow it to move.

Of course, backing the screw out a few turns will allow the yoke to move, but that was the case with the old type screw as well. With the screw properly tightened, I am not sure I see how "numerous" cases of the cylinder falling out would happen, but maybe I am missing something.

Jim

 

[Drail]

I think that if properly fitted the old solid screw was much better than the plunger type. IMO the biggest problem with the sideplate screws is uninformed guys putting them in the wrong hole and cranking down on them. That can distort the precision fitting done on the crane screw - and that hand fitting was very important. Know your holes.

 

[MrBorland]

Jim - You raise a good point, but first, lemme recommend against trying to test the system by pushing the cylinder off the frame, since the test can lead to a bent plunger, and trouble later, or, if your test is successful, a galled V-groove. If this happens, the yoke can move past the plunger just a bit easier and easier, and fixing the gall necessitates a trip back to S&W for a new fitted yoke.

At any rate, the plunger might be bottomed out when turned all the way in, but this would somewhat defeat the purpose of this design in the first place. And this type of failure, while not exactly common, is far from unheard of among wheelgunners who compete in runNgun competition. Fast reloads can specifically strain this area when a weak-hand reload is used. This is especially true when using a speedloader is used to slam those rounds home. The impulse force of a fast weakhand speedloader slam is likely quite a bit higher than when one gives a firm, but constant test push from behind. If you want to realistically test the system, do it this way (i.e., weakhand speedloader while the timer's running), though I don't recommend it.

And while failures could be the result of a loose screw, I have personally witnessed a friend of mine launch the cylinder of his brand-new 686SSR when he used a speedloader and his weak hand to slam those first rounds in. I didn't inspect the screw to see if it was fully tightened, but I'll assume it was screwed all the way down at the factory. The plunger did gall the "V" on the yoke, though, so his brand new SSR went back to S&W for a new yoke.

 

[rswartsell]

I know by experience that by spending a number of years shopping for, shooting and appreciating older Smith and Wessons that at least SOME of them (with me rejecting poor performers and dealing with well burnished "veteran" actions) are the very best revolvers (lesser quantity to classic Colts) I have personally seen.

Obviously (to me anyway) I do not have the coin to go through modern production Smiths in enough quantity to make a meaningful study of the proposition.

I have no objection to MIM on principal. I owned a Colt Mk III and while I didn't expect a Python I found no reason at all to complain. I KNOW the old Smiths and personally prefer them. I am well qualified to be an "Old Fart".

While the average new production Smith may very well be an advancement on the basis of consistency, you will play hell to prove that are better than my "pick of the litter" veterans.

 

[Elkins45]

I recall reading an article in the summer of 1989 about S&W's new engineering efforts to strengthen the Model 29 so they wouldn't shoot loose in 1000 rounds of silhouette competition. This was said to be one of the reasons they were going to be able to offer a lifetime repair policy on the new guns.

One of the changes mentiond in the article was the elimination of hand fitting of the yolk, allowing them to be made stronger. The self-tensioning yolk retention screw was one of the changes that allowed the stronger yolk to be used. So it has since become one of the ways to tell if a used gun was made before or after the lifetime service policy was instituted. Or so I am told.

If memory serves the article was in American Handgunner and the author was Massad Ayoob. I am confident on the date because it was what prompted me to buy my Model 29.

 

[rcmodel]

This got me to wondering tonight.
So I pulled the cranes out of a 'well loved' 1997 317 Airlite, and a 2000 625-6 .45 ACP to see what's up?

The 625-6 shows no signs of wear, and hardly a shiny spot on the crane V-notch were it rubs when opened & closed.
Despite having a lot of full-moon clips of 230 grain ammo slammed in it fast.

The 317 crane does show wear, even a groove where the plunger rubs on it.
It has never been speed loaded ever.
But the crane is aluminum.

The other thing I hadn't realized before is that the spring plunger crane screws have larger heads and cannot be put back in the wrong side-plate holes.

So, that IS an improvement!

PS: The spring and plunger in the N-Frame is bigger, longer, and stronger then the one in the J-Frame.

rc

 

[Jim K]

Interesting on the cylinder being "launched". I didn't just push, I used a rubber mallet to try to drive the cylinder forward, and it did not fly away. I doubt any "slamming" of a speed loader would generate more force, but I am not your friend. Any way, no galling, but I don't plan to keep doing it either.

Certainly, I would expect S&W to come up with a solution. If the problem is so serious that one person has seen numerous failures, there must be many hundreds nationwide.

I will note that enough forward force on the yoke with the old system will cause dents in the yoke slot where the screw sits, the same as the galling in the new yokes.

Jim

 

[rcmodel]

I know for sure I have repaired a lot more galled old style cranes and buggered screws then I ever saw with the new style spring loaded ones.

Always due to all the wrong screws put in all the wrong holes.

(But I don't get out much anymore.)

However, if your S&W crane & cylinder fly off down range during a speed-load?

You might need to reduce your Steroid injections about 50cc a day!!

rc

 

[MrBorland]

The problem, when I've seen it, most often occurs with push-release speedloaders used during a weakhand reload. I've got many thousands of reloads on my 686 using JetLoaders, and I've never had a problem, and the plunger is still good and straight, but my default reload is the stronghand reload, where the cylinder's largely supported against the force of the rounds getting slammed in. I've heard of it happening with moonclips in matches, but it seems to me to be less often. If true, it could be because the rounds are dropped - not slammed - into placed. My default moonclip reload is a weakhand reload, and I've not yet had a problem, though I should note that I shoot a moonclipped gun much less than a speedloader-fed gun.

If the problem is so serious that one person has seen numerous failures, there must be many hundreds nationwide.

I mentioned earlier I thought the yoke screw is the Achilles heel of the S&W revolver, and that the newer design made it more so, but that wasn't to say or imply that it is or will be problem for general use. The whole design is robust enough for general use, it seems. Competition has a way of pushing things to their limit, though, and yoke screw failures I've seen have been in that context. From what I've seen, it's common enough to be of concern in competition, but generally not enough of an issue for S&W to worry. It's just something to be aware of.

 

[Jim Watson]

The yoke arbor jumping the spring plunger may not be very common or likely in every gun, but it does happen every now and then; I have seen it happen once or twice.
Competitive shooters run their guns more and harder than John Q. Public.

 

[Elkins45]

I bought a 38/44 heavy duty that when you opened the cylinder it would fall out. There was a half moon missing from the yolk where the screw butts against it when open. I wonder how that happened? I had to weld it up to fix it.

I never did find the detent pin after I launched it the first time. One of these ays I'm going to make a replacement....one of these days.

 

[Peter M. Eick]

You can make your pre-war N frame yoke pin out of a nail, but round it first and soften it first so it does not gauge the frame. You want the pin to be the wear point. Bic pens make great springs for yoke pins also.

 

[joebiker]

Thank you..

Driftwood Johnson for taking the time & effort to do this thread.
Can't imagine the time spent taking incredibly sharp photos, writing detailed comparisons of parts, and responding to questions as well. Your effort is appreciated.
As an owner of a Model 617, I'd wanted a K-22, or 17 for many years..
even the 617 was "out of my price range".. not that I couldn't afford it, just unwilling to spend that much money on a new pistol..so waited years until I found a nice used one..

I am impressed with your explanation of MIM parts & their use in the firearms industry. I does leave a somewhat sour taste when I view the cost-cutting methods employed by S&W, & others using production "improvements" to cut labor & production costs, yet the price of these products continue to escalate.

I am truly shocked @ the MSRP of S&W's current pistols.. a 617 ? $829 ..