I don't have all the information to correctly ask this question, but here are the basics.

My brother got a 22 caliber revolver for his wife. As I recall, he wanted one with 10 rounds, but it had less, so "they" switched cylinders to give him what he needed.

My first impression is that one can't do that - all the parts are supposed to be fitted to each other. Anyway, one of his complaints now is that when his wife shoots it, it gets absolutely filthy around the forcing cone area.

I don't have any of my tools with me to measure this, but it looks to me to be something between 1/64th inch and 1/32 inch gap. It is huge. On all the revolvers I've had experience with, there was barely enough gap to see between the two parts.

If more information is needed, I can post it.

My question, if I'm right about this, how do we go about fixing it, or does it need to go back to a gunsmith? What type of gap should there be between cylinder and forcing cone.


(Everything I think I know about S&W revolvers is that the parts are (or at least used to be) hand fitted to each other, and you don't drop in a replacement part without fitting it to the gun.....)

1/64th would be .016 ( rounded up) and 1/32nd would be .031( rounded down ) . If I remember correctly max "within spec" barrel/cylinder gap is .012. So both would be too much.

I would be more concerned with what was actually done.Was it done by a gunsmith ? The cylinder/barrel gap by itself is only part of the job. The inner workings of the gun would also need to be changed as part of the cylinder swap from a 6 to a 10 if I remember correctly ( i honestly am not even sure that a swap like that is something that COULD be done correctly). Others will surely be in that have more info.

__________________
1st smiles,lies.Last,gunfire.

I am certainly not a qualified gunsmith, however it seems that switching from something less than a 10 shot cylinder to a 10 shot cylinder requires a a qualified gunsmith to adjust and fit a new hand and cylinder stop to properly adust the timing. The amount of rotation will be less on a cylinder with more rounds. If the chambers don't line up properly with the barrel and forcing cone, you may have disastrous results.
That being said, to answer your original question, you can use a feeler gauge to measure the barrel / cylinder gap. I usually see references of .004 to .007 inches as being proper. The large gap which you eyeballed might actually have avoided a catastrophe because the bullet might have had more room to "find" the forcing cone rather than striking the receiver. I would find a gunsmith to check it out before your friend is injured.

I made my 617 a 6 to 10 shot convertible. What is required is that the cylinders be of the same length on the outside, with the same depth of counterbore on the inside where the end of the yoke goes, and a different hand. The cylinder stop remains the same. The top nose of a 10 shot hand is much thinner than for a 6 shot, due to the much shorter distance the 10 shot moves when it indexes.

It's easier to just fit a different cylinder than have 2 that are exactly alike, because then the gun can just be modified to fit the new one only.

Ideally, the gap should be .006.

On cylinder gap and Plus, occasionally even going from 6 shot to 6 shot take a small amount of adjustment.fit on the yoke tube, sometimes you get lucky and sometimes you don't. Occasionally the hand or ratchets also need a bit of adjustment. I am sure like Toolguy says a 6 to 10 would take some hand adjustment after the cylinder was set up on yoke and barrel gap adjusted.

Go to the Auto Parts store or Harbor Freight and buy a set of feeler gauges. Easy to measure the gap. I have older guns with as much as .017 and they shoot fine. You need to worry about end shake and throat to bore alignment. If the gap is to huge the barrel must be removed, the shoulder trimmed to seat the barrel further into the frame. Since the barrel has to make a complete revolution to bring the front sightback in alignment with the rear sights the bore end of the barrel now has becut down. Once the proper gap is finally set, then the bore end of the barrel has to be chamfered.

I'd suggest putting the correct cylinder in and trading it for the gun he wants.

Most knowledgeable folks will tell you that .004-.006 is ideal. Today the factory says that .012 is ok, but that’s only been since they became too sorry to properly fit parts. That would require skilled labor. I don’t think S&W has much of that available these days.

As an aside, seeing as how this is now and I'm coming from then, the proper/best gap for a .22 may very well be smaller than for larger calibers---or so it is implied in S&W's 1925 catalog---where they are singing the praises of "THE 22-32 HEAVY FRAME TARGET REVOLVER", and wherein they state: "The double locked cylinder design of all S&W swing out cylinder models is especially productive of results in the .22 as with it alignment is kept perfect, while the closeness with which we fit our cylinders to the barrel prevents loss of power and makes uniform shooting certain."

So----how close is close? As luck would have it, I have one of those "22-32 HEAVY FRAME TARGET REVOLVER"(s)----and it's as new----and it's from 1927-----so close enough.

And the gap is-------------------about as nice a .004" as you're going to feel.

And that, dear reader, is some of what they're talking about when they say "the good old days"----gone, but not forgotten.(!!!)

Ralph Tremaine

Dunno about rimfire, but center fire headspace range is 0.060-0.068 inch, barrel/cylindger gap (old school) is 0.003-0.008 inch. You should have the headspace feeler in place to keep the cylinder still while you measure the barrel/cylinder gap. Unless you're checking end play, in which case you measure & record with and without the headspace feeler.

If all the sale folks did is swap cylinders, they need to get their dealership revoked. They didn't sell him what he needed, they sold him what he wanted. There's a big difference done like they did. I'd suggest a trip back to the factory along with a note about what was done and by who.

I am getting too many different stories about the past - the gun was ordered to be 10 rounds, but showed up at the dealership for 6. Somehow, someone swapped cylinders, and someone from S&W said all was find. As far as I'm concerned it's very much not fine, and I've read too much about making sure all the components of a S&W gun work together properly. I would have sent it back, and had them order the correct gun. At any rate, they don't want to deal with it, and my asking questions brings up questions of why I want to do anything about it. The gun is just sitting now, not being used. Next time I visit I'll bring my feeler gauges with me, and measure the gap. It looks huge to my eyes.

Thanks for the help, but none of this is going to be helpful, at least not until I get a real measurement to post here, which won't be until February next year at the soonest...... :-/


This is the video that got me to wondering about the issues this gun has. Very long, and very thorough video, and I learned a lot from it:
YouTube

I've always read that .004 to .006 was what one should be looking for.
My father always told me that I didn't study in the right branch so as to be able to show the manufacturers engineers how to do their job...but I always thought that I'd show the Old Man he was wrong.
When I bought my first Dan Wesson,I adjusted the gap at .0015...and the thing started having cylinder lock up from carbon build up after a few rounds(100-75,less when using a dirty burning powder).
Lesson 1:.004 to .006'' is now fine with me
Lesson 2:the Old Man was right(again).

.005 to .006 is fine with me especially if you are shooting soft cast lead. My old Smiths are .004 to .006.

My new one, is about .010 but is still quite accurate. I'd prefer the numbers in your Lesson 1 for sure!

Our new M460 Carry measures .006” - .007”.
Accuracy with some 460 brass/bullets was fine at 10 yds and 50yds........ Rem 250g LRN Colts at 10yds was sad and at 50yds
...... I repeated my screen name 40 times or so.

My 69 is 0.003" and my 66-8 0.007. Ballistics by the Inch has some data on gap vs velocity. Bottom line: once a gap exists it doesn't matter significantly whether its 0.001 or 0.006.

To me, visually, this gap looks excessive. I can't measure it until I return, with feeler gages, but any thoughts on this photo? I've not seen this much of a gap on my guns...

Attached Images

IMG_1165.jpg (65.5 KB, 57 views)

Yes that looks prety big. When I am checking out a gun, I hold it up to a light and look at the gap. You have to hold the gun just right to see the thin gap. Hard to get a decent picture of a tight gap.

For me, taking the photo was the easy part. I didn't have any tools with me, but I think I can get cameras to do most anything.

I did what you suggested pretty much, but I held the gun in front of something white, then used my iPhone set for 2X magnification, and took several photos until I liked one of them.

Unless you guys think this is dangerous, I'm going to drop out of the discussion with the owner. He is happy with it, and told me S&W thought it was fine. I've read too much about S&W revolvers to accept any of that. To me, if it came with a 6-chamber cylinder, I'd have left it like that.