M638 Issues

[JayFramer]

Recently got an M638-2 made in 1997. Revolver is in superb cosmetic condition and came with original box and papers, looked fired very little. I am noticing a couple things about it that I'd like to ask about. First some pictures:

Gap between frame and yoke:





The ejector from below:



There is no endshake or excessive cylinder play, and timing is perfect. Cylinder gap seems a little high with .009" on the right side (when looking down the sights) and .008" on the left. All chambers seem to line up well with the bore when looking down it and with the trigger held back. I have not fired the revolver yet to see if it spits lead.

So I am wondering if this is just some lackluster fitting on this particular revolver, or is this going to cause problems during firing? Do I need to send it back to the factory? I bought this as an EDC CCW weapon and need to make sure it isn't going to let me down.

Let me know what you make of the pictures. Thank you!

[scooter123]

Remove the grips and look for matching assembly numbers on the side of the grip frame and the surface of the yoke opposite the model number stamped in the recess. If you don't find a match you have a revolver that was assembled using mismatched parts, specifically a yoke fitted to a different frame.

If you do find matching number then I think you should contact S&W, because that is the worse job of fitting yoke and frame I have EVER seen. It is so bad I have a hard time believing these two parts were ever fitted together.

[JayFramer]

Originally Posted by scooter123

Remove the grips and look for matching assembly numbers on the side of the grip frame and the surface of the yoke opposite the model number stamped in the recess. If you don't find a match you have a revolver that was assembled using mismatched parts, specifically a yoke fitted to a different frame.

If you do find matching number then I think you should contact S&W, because that is the worse job of fitting yoke and frame I have EVER seen. It is so bad I have a hard time believing these two parts were ever fitted together.

The number opposite the yoke is "425" and the ones that are underneath the stocks are "B15" which is easy to see and "21562 360" which is quite faint. The numbers don't match.

[ExcitableBoy]

It appears to be a sprung yoke, usually caused by some yahoo doing the Hollywood flip the cylinder into battery with a flick of the wrist. About the dumbest thing to do other than smacking it with a hammer. A fix by a competent gunsmith would be in order. Better yet, call the guy out on it and get your cash back.

[JayFramer]

Originally Posted by ExcitableBoy

It appears to be a sprung yoke, usually caused by some yahoo doing the Hollywood flip the cylinder into battery with a flick of the wrist. About the dumbest thing to do other than smacking it with a hammer. A fix by a competent gunsmith would be in order. Better yet, call the guy out on it and get your cash back.

How much would it cost to get this fixed at the S&W factory? Since it is a no-lock model, I'd rather just get it fixed. These 638 no-locks are hard to find.

Also, in the meantime, would it be safe to carry?

[ExcitableBoy]

JAY:

I couldn't quote you $$$ on the fix. Realignment is kind of a touchy thing. Best to give S&W a call, or/also find a well recommended gunsmith who has a good rep with S&Ws, and compare costs and turnover time. At least with a local GS you would have instant feedback on function and fit once the work has been completed.

I would not recommend shooting it as is. At the least, it may be shaving bullets and spitting shrapnel from the cylinder/forcing cone gap.

[JayFramer]

Originally Posted by ExcitableBoy

JAY:

I couldn't quote you $$$ on the fix. Realignment is kind of a touchy thing. Best to give S&W a call, or/also find a well recommended gunsmith who has a good rep with S&Ws, and compare costs and turnover time. At least with a local GS you would have instant feedback on function and fit once the work has been completed.

I would not recommend shooting it as is. At the least, it may be shaving bullets and spitting shrapnel from the cylinder/forcing cone gap.

Guess I'll give the factory a call and see if they can give me a quote. A shame they don't offer the new 638s without locks... you don't think they'll install a lock if I send them this gun do you, or is that even possible?

[ExcitableBoy]

JAY:

Nope... it would come back as OEM unless there is a dire need for replacement parts. No retrofit of a lock.

[cadmike]

I think that kind of fit is not uncommon with the airweights. You should see how it shoots before returning it. It's probably fine.

[JayFramer]

Originally Posted by cadmike

I think that kind of fit is not uncommon with the airweights. You should see how it shoots before returning it. It's probably fine.

Really? I might go to the indoor range tomorrow and see. I'm rather upset that this gun has this issue. I looked it over at my dealers store before I took it home, but then noticed it today. I have been looking for a 638 without a lock for a long time so I am quite saddened.

[JayFramer]

I am concerned about the mismatched frame and cylinder assembly. Like I said the assembly number on the yoke does not match the ones on the grip frame...

[Old cop]

I've noticed in passing that the older S&W seem to have a better fit of yoke to frame than the newer ones.

[Arik]

Here is my 642. Bought last year new by me. Has about 300 rounds



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[Protocall_Design]

Judging by the pictures, if it were mine, I would just finish fitting the crane to the frame by filing material at the 7-8 o'clock position where the crane is touching the frame. This would allow the centerline gap to close and bring everything in line. There are other ways to address the problem, this is probably the cheap and easy fix, other than sending it back.

[JayFramer]

It's weird to me that the assembly numbers are not matching on this gun. What does that mean? Did the yoke or cylinder get replaced sometime or did it leave the factory like this?

[GeoJelly]

Gunsmith I am certainly not - but neither Arik or JayFarmer's yoke-to-frame situation looks right. On all of my J-frames, the top portion of the yoke, where the ejection rod passes thru, is butted up against or seated against the frame. Granted, as has been mentioned, S&W's haven't had the near-seamless yoke-to-frame fitting for many, many years. But, my 637 looks about right (unlike me! ) and so do my other aluminum J-frames. If it were mine, I would at least attempt to return it, and if not, I would send it in before I fired it...

Edited to add: comments weren't made to disparage anyone - just an opinion

[Arik]

You know I never gave it any thought. Gun worked so I was fine. I'm used to looking at semi autos which never have seamless fit

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[JayFramer]

If I attempt to contact the seller for a refund, should I mention the mismatched assembly numbers?

I will probably use the money to just buy a new production 642-1 no-lock like I used to have. I know they aren't supposed to be as good as a pre-lock era gun, but my old one gave good service and if I remember correctly never spat lead and was very accurate. If it has problems, at least I know S&W should fix it under warranty.

[Arik]

Good luck getting your money back.

I can say that if i were the seller I wouldn't. Simply because I would never have thought about the different assembly numbers and I honestly wouldn't​ know if mine had that too. Most people buy guns and if there are no obvious major defects and it functions at the range they don't​contact the company or dig any further into the assembly numbers. I would think you just had buyer's remorse.

If I were you I'd go to a gun store first and check out what they have and if theirs looks the same

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[JayFramer]

I'll probably just sell it and make my money back, of course noting the fitment of the yoke in the auction.

Oh well, not the first time I've had to flip a gun like this.

[AlHunt]

It kind of depends on the seller, whether it was a private sale, Gunbroker or something else, the terms of the sale and whether maybe you got a below market killer deal.

It seems like a reputable dealer might be willing to refund or maybe share the cost of the repair. You have nothing to lose by asking.

[Arik]

Before selling I would consider looking around at a gun store, you have nothing to lose. You saw yours, I showed you mine.....and mine has a few hundred rounds. Maybe they're just built like that.

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[AlHunt]

Originally Posted by JayFramer

The number opposite the yoke is "425" and the ones that are underneath the stocks are "B15" which is easy to see and "21562 360" which is quite faint. The numbers don't match.

Wait a minute. Aren't "opposite the yoke" and "under the stocks" both on the frame?

Maybe I'm not understanding something. Is there an assembly number on the yoke itself?

[JayFramer]

Originally Posted by AlHunt

Wait a minute. Aren't "opposite the yoke" and "under the stocks" both on the frame?

Maybe I'm not understanding something. Is there an assembly number on the yoke itself?

Yeah sorry about the wording. What I meant to say was the assembly number itself which is on the yoke does not match the number on the grip frame.

[JayFramer]

Originally Posted by Arik

Before selling I would consider looking around at a gun store, you have nothing to lose. You saw yours, I showed you mine.....and mine has a few hundred rounds. Maybe they're just built like that.

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According to those above who know much more about these guns than I as well as various research tells me the yoke is absolutely not supposed to have this massive gap in it.

[cadmike]

Jayframer I thought I'd post a pic of my 638 for your review. I don't think it looks any different than yours or ariks. I can't speak to the assembly numbers. I'm not trying to dissuade you one way or the other but honestly I don't see a real problem. If I were you I'd get some .38s with lead bullets and try them out. If it spits lead than obviously you have a problem. Otherwise, you've got yourself a solid gun. Good luck.

[cadmike]

For what it's worth the round count on my gun is well north of 1000. FYI.

[JayFramer]

Thanks, gang. It's just a real mystery to me why those numbers don't match... smells fishy...

[Arik]

I'll check the numbers on mine when I get home

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[cadmike]

The assembly numbers on mine do match. Perhaps your gun went back to smith at some point and they swapped out the yoke/cylinder assembly for new. Perhaps a phone call to them would verify.

[AlHunt]

Out of morbid curiosity, I got my Model 38 from about 1985 out. The Yoke/Frame fit is tight and the assembly number on the yoke matches the frame. Pic attached.

[Arik]

Originally Posted by JayFramer

The number opposite the yoke is "425" and the ones that are underneath the stocks are "B15" which is easy to see and "21562 360" which is quite faint. The numbers don't match.

Unfortunately I can't take off the grips. Don't have a allen ranch small enough. However the number opposite of yoke is 622 which are not part of the S#

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[ExcitableBoy]

Newer alloy frame J's definitely do not have the fit of their older steel predecessors. My 438 has about .002" gap just below the ejector rod, but locks up tight with no play at all. What should be of concern is the misalignment of the ejector rod-to-barrel lug and detent, plus the non-concentricty of the ejector rod into the yoke bearing surface. The cylinder may be cocked slightly in the frame, exhibited by the e-rod alignment. By eyeball, you can see way more than a few thousandths out of kilter. This could cause problems down the road, even if there is currently no lead shaving.

Easiest way to determine if the chamber-to-forcing cone alignment is within spec is to have a gunsmith check it with a Go-No-Go gauge.

[GeoJelly]

Originally Posted by ExcitableBoy

Newer alloy frame J's definitely do not have the fit of their older steel predecessors. My 438 has about .0002" gap just below the ejector rod, but locks up tight with no play at all. What should be of concern is the misalignment of the ejector rod-to-barrel lug and detent, plus the non-concentricty of the ejector rod into the yoke bearing surface. The cylinder may be cocked slightly in the frame, exhibited by the e-rod alignment. By eyeball, you can see way more than a few thousandths out of kilter. This could cause problems down the road, even if there is currently no lead shaving.

Easiest way to determine if the chamber-to-forcing cone alignment is within spec is to have a gunsmith check it with a Go-No-Go gauge.

I hadn't noticed that in his photo until you mentioned it! If the barrel is on straight - then the ejector rod is noticeably out of whack. And, that would explain the left-right difference in B/C gap. Now I'm going to have to check my J's ...

Edited to add: I envy your calibrated eyesight - you are able to distinguish 2/10,000ths??

[ExcitableBoy]

GEO:

OOPS! One too many zeroes... I will edit.

Thanks.

[JayFramer]

I should also mention the gap widens when I put pressure on the opposite side of the cylinder.

Clearly, the gun I bought is a dud. I am selling it with a disclaimer and plan to use the cash for a new 642 no-lock.

[ExcitableBoy]

I'm sure that the gun was fine when new. It deserves repair. The "dud" was a previous owner.

[JayFramer]

Originally Posted by ExcitableBoy

I'm sure that the gun was fine when new. It deserves repair. The "dud" was a previous owner.

This might be true. But the fact that the cylinder/yoke is obviously a replacement. I smell a rat, like maybe the original owner blew up the cylinder or otherwise damaged it and threw a replacement on to it that wasn't fitter properly. Not sure.

[GeoJelly]

It sure looks like a replacement yoke to me - the fit just doesn't look right. I had the good fortune of picking up a used 640 yesterday - it had the correct box so I know it was made in 2016. I just thought I'd post one more photo to show that S&W can do a great job of fitting and finishing J-frames - even up to 2016. OK - so it doesn't have the hair-line seam of the old days Smiths - but it looks great to me!

[ExcitableBoy]

In Photo #1, you can see where the open side of the frame at the yoke pivot is tweaked. Alloy frames are relatively malleable compared to steel. If it were mine, I'd make a jig and chuck it up in a large vice between two chunks of wood and give it an educated whack with a medium ball peen hammer, driving about a 12" long, 3/4" dowel of rock maple or white oak toward dead-center of the barrel. Simple eyeball geometry will show you at which point to strike... the frame is clearly curled slightly away at the open side of the yoke pivot point, maybe about a 1/4" section at the 5 o'clock position, per the pic. This would clearly get everything back to where it should be. It's just a matter of getting the right setup for the procedure. Some gunsmiths have a jig for doing just such a thing. It's pretty much like tightening up the slide on an old and worn 1911, of which I've done a time or two.

It ain't rocket science.